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DENTAL  Pathology  AND  imlfii^BU^^ 


INCLUDING 


PHARxMACOLOGY. 


BEING 


A  TREATISE  ON  THE  PRINCIPLES  AND  PRACTICE 
OF  DENTAL  MEDICINE. 

FOR  STUDENTS   AND   PRACTITIONERS. 


BY 

HENRY  H.  BURCHARD,  M.D.,  D.D.S., 

SPECIAL   LECTURER  ON   DENTAL    PATHOLOGY  AND   THERAPEUTICS   IN   THE 
PHILADELPHIA    DENTAL   COLLEGE. 


ILLUSTRATED  WITH  388  ENGRAVINGS  AND 
TWO  COLORED   PLATES. 


LEA   BROTHERS   &   CO.. 

PHILADELPHIA  AND  NEW   YORK, 

1898. 


Entered  according  to  Act  of  Congress  in  the  year  1898,  by 

LEA   BROTHERS    &   CO., 

in  the  Office  of  the  Librarian  of  Congress,  at  Washington.     All  rights  reserved. 


WESTCOTT    &    THOMSON, 
ELECTROTYPERS.     PHILADA. 


DEDICATED  TO 
G.  V.  BLACK,  M.D.,  D.D.S.,  D.Sc, 

TO  WHOM  RATIONAL  DENTAL  PATHOLOGY  OWES  SO  MUCH, 

AND  TO 

DR.  EDWARD   C.  KIRK, 

TO  WHOM  DENTAL  SCIENCE  OWES   MUCH  AND  THE  AUTHOR  OWES 
MORE  THAN  HE   CAN   EVER  REPAY. 


PREFACE. 


This  volume  is  designed  as  a  text-book  of  the  principles  and  prac- 
tice of  dental  medicine  for  the  use  of  students,  and  as  a  reference  work 
on  applied  special  pathology  and  therapeutics  for  the  use  of  dentists. 
Accepting  the  dictum  of  the  advanced  teachers  of  the  day,  the  writer 
believes  that  an  entirely  rational  system  of  dental  medicine  can  have 
but  one  basis — namely,  the  same  principles  which  underlie  general 
medical  and  surgical  practice.  The  book  represents,  therefore,  an 
attempt  at  formulating,  from  data  obtained  from  every  available  source, 
a  system  of  dental  pathology  and  therapeutics  of  which  the  several 
parts  shall  be  in  harmony  with  one  another  and  also  with  the  several 
collateral  sciences  involved.  The  impulse  prompting  the  work  was  no 
desire  to  multiply  books,  but  arose  from  a  conviction  expressed  by 
many  teachers,  that  such  a  volume  is  needed  by  students,  practitioners, 
and  teachers. 

The  extent  and  scope  of  references  may  be  only  partially  seen  in  the 
numerous  foot-note  references,  space  limitations  precluding  any  ex- 
haustive bibliography. 

It  would  be  unjust,  however,  to  omit  this  opportunity  to  credit  two 
investigators  without  whose  researches  this  volume  would  have  been 
impossible  :  Professors  G.  V.  Black  and  W.  D,  Miller,  to  whom  fre- 
quent and  specific  references  are  made. 

The  immense  development  of  modern  dentistry  has  brought  with  it 
a  more  rational  and  convenient  grouping  of  its  subjects.  The  American 
Te.vf-BooJcs  of  Operative  and  Prosthetic  Dentistry  have  already  won 
acceptance,  each  in  its  own  field.  They  leave  untouched  a  range  of 
subjects  which  are  naturally  cognate,  and  hence  are  most  advantageously 
taught  in  conjunction — namely.  Dental  Pathology,  Therapeutics,  and 
Pharmacology.     The  fitness  of  this  grouping  is  manifest. 

Special  thanks  are  due  the  publishing  department  of  the  S.  S.  White 
Dental  Manufacturing  Co.  for  their  liberality  in  furnishing  illustrations ; 


6  PREFACE. 

thanks  for  cuts  are  also  tendered  G.  V.  Black,  J.  S.  Marshall,  J.  L. 

Williams,  Wm.  Wood  &  Co.,  and  P.  Blakiston,  Son  &  Co. 

The  author  tenders  to  Ijea  Brothers  &  Co.  his  grateful  thanks  for  the 

more  than  liberal  spirit  exhibited  by  them  in  the  making  of  the  book  ; 

from  beginning  to  end  their  course  has  been  one  of  great  courtesy  and 

unbounded    generosity. 

H.  H.  B. 

April,  1898. 


I 


CONTENTS. 


SECTION   I. 
GENERAL   PATHOLOGY. 


CHAPTER  I. 


PAGE 

GENERAL  PEINCIPLES 17 


CHAPTER  II. 

CAUSES  OF   DISEASE,  GENERAL   AND  LOCAL 28 

CHAPTER  III. 

BACTERIOLOGY,  WITH    SPECIAL   REFERENCE   TO    DENTAL    PATH- 
OLOGY. AND   THERAPEUTICS 37 

CHAPTER   IV. 
DISTURBANCES   OF   NUTRITION:   ATROPHY,  DEGENERATION,    NE- 
CROSIS, HYPERTROPHY,  TUMORS 51 

CHAPTER   V. 
DISTURBANCES  OF  THE  VASCULAR  SYSTEM 69 

CHAPTER  VI. 
INFECTIVE    INFLAMMATIONS:   SUPPURATION,    ABSCESS,    FEVERS, 

SEPTICEMIA,  AND  PY.EMIA 89 


8  CONTENTS. 

SECTION  IL 
ANATOMY  AND  DEVELOPMENT. 


CHAPTER  VII. 

PAGE 

THE  DEVELOPMENT  AND  STKUCTURE  OF  THE  JAWS  AND  TEETH  101 

CHAPTER  VIII. 

THE  SURGICAL  ANATOMY  OF  THE  TEETH 141 

CHAPTER  IX. 

DENTITION:   ITS  PROGRESS,    VARIATIONS,  AND  ATTENDANT  DIS- 
ORDERS  180 

CHAPTER  X. 

MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH 206 


SECTION   III. 
AFFECTIONS    OF    ENAMEL   AND   DENTIN. 

CHAPTER  XI. 

AFFECTIONS  OF  THE  ENAMEL  - 243 

CHAPTER  XII. 
DISEASES  OF  THE  DENTIN 260 

CHAPTER  XII  (Continued). 
DENTAL  CARIES 264 

CHAPTER  XIII. 
DENTAL  CARIES :   ITS  CAUSES  AND  CLINICAL  HISTORY 273 

CHAPTER  XIV. 
DENTAL  CARIES:  PATHOLOGY  AND  MORBID  ANATOMY 290 

CHAPTER  XV. 

DENTAL  CARIES :    DIAGNOSIS,  SYMPTOMS,  AND  PROGNOSIS   ....    304 

CHAPTER  XVI. 
DENTAL  CARIES:  THERAPEUTICS  AND  PROPHYLAXIS 313 


CONTENTS.  9 

SECTION  IV. 
DISEASES    OF   THE   DENTAL   PULP. 


CHAPTER  XVII. 

PAGE 

CONSTRUCTIVE  DISEASES 327 

CHAPTER  XVIII. 

DESTEUCTIVE  DISEASES  OF  THE  DENTAL  PULP 341 

CHAPTER  XIX. 
CHRONIC  DEGENERATIONS  AND  DEVITALIZATION  OF  THE  PULP  .    362 

CHAPTER  XX. 

GANGRENE  OF  THE  PULP 381 


SECTION  V. 
DISEASES    OF   THE   PERICEMENTUM. 


CHAPTER  XXI. 
SEPTIC  APICAL  PERICEMENTITIS   (ACUTE) 1 393 

CHAPTER  XXII. 

SEPTIC  APICAL  PERICEMENTITIS  (CHRONIC) 407 

CHAPTER  XXIII. 

NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS .423 

CHAPTER  XXIV. 

PERICEMENTAL  DISEASES  BEGINNING   AT  THE  GUM-MARGIN    .    .    444 

CHAPTER  XXV. 

PYORRHCEA  ALVEOLARIS 459 

CHAPTER  XXVI. 

DISEASES  OF  THE  PERICEMENTUM  BEGINNING  UPON  A  LATERAL 
ASPECT  OF  THE  TEETH 477 


10  .  CONTENTS. 

SECTION  VI. 


CHAPTER  XXVII. 

PAGE 

DISEASES  OF  THE  DECIDUOUS  TEETH  AND  THEIK  TKEATMENT  .    491 

CHAPTER  XXVIII. 

KEFLEX  DISORDERS  OF  DENTAL  ORIGIN 500 

CHAPTER  XXIX. 

INFECTIONS  OF  AND  FROM  THE  MOUTH,  AND  STERILIZATION  .    .    511 


SECTION  VII. 

DENTAL  PHARMACOLOGY  AND  DENTAL  MATERIA 

MEDICA. 


DENTAL  PHARMACOLOGY 529 

DENTAL  PHARMACOPOEIA 545 


5^    ^ 


Mem  ^' 

DENTAL  PATHOLOGY, 
THERAPEUTICS,  AND  PHARMACOLOGY. 


SECTION  I. 

GENERAL  PATHOLOGY. 


CHAPTER   I. 
GENERAL  PRINCIPLES. 

The  study  of  dental  pathology  and  therapeutics  embraces  a  con- 
sideration of  such  principles  of  general  pathology  and  therapeutics  as 
find  application  in  the  practice  of  dentistry,  and  in  addition  implies 
and  requires  an  exhaustive  investigation  into  the  modifications  of  these 
general  principles  growing  out  of  the  peculiarities  of  anatomical  struc- 
ture and  the  functions  of  the  parts  included  in  the  field  of  operation. 
There  is,  perhaps,  no  aspect  of  surgery  in  which  these  modifications  of 
treatment,  due  to  anatomical  peculiarities,  are  more  marked  than  in 
dental  therapeutics. 

A  consideration  of  the  special  practice  must,  however,  be  preceded 
by  a  study  of  the  general  disease-processes  which  affect  the  tissues  of 
the  body ;  so  that  a  special  application  of  the  knowledge  thus  gained 
may  be  made  to  render  clear  the  nature  of  dental  diseases  and  the 
rationale  of  their  treatment. 

The  word  pathology  is  derived  from  the  Greek  patJws,  disease,  and 
logo><,  a  treatise  or  discourse.  Applied  in  its  general  sense,  it  includes 
a  study  of  the  natural  history  of  diseases,  their  causes,  progress,  phe- 
nomena, and  terminations.  The  word  therapeutics  is  derived  from  the 
Greek  therapeuein,  to  take  care  of,  meaning  the  measures  adojited  to 
remedy  or  remove  the  changes  induced  by  pathological  processes. 

Pathology,  as  has  often  been  stated,  cannot  be  pursued  as  an  inde- 
pendent study,  for  it  is  but  an  expression  of  other  collateral  sciences. 
It  is  a  perversion  of  the  processes  found  associated  with  what  are 
termed  living  bodies  ;  in  its  full  and  philosophical  sense  it  is  morbid 
biology — an  altered  physiology.  It  follows,  therefore,  as  a  corollary, 
that  an  exhaustive  flimiliarity  with  the  contemporary  state  of  the  science 
2  17 


18  GENERAL  PRINCIPLES. 

of  physiology  is  necessary  to  a  clear  comprehension  of  the  nature  of 
pathological  processes.  The  more  minutely  an  investigator  j^roposes  to 
examine  into  pathological  states,  the  more  extensive  must  be  his  parallel 
knowledge  of  physiology.  While  many  phases  and  features  of  path- 
ology may  be  grasped  by  a  student  of  but  two  courses,  there  are 
problems  in  modern  pathology  that  test  and  exceed  the  resources  of 
the  veteran  of  the  physiological,  chemical,  and  pathological  laboratory. 

Whatever  field  of  medicine  or  surgery  may  be  under  systematic 
exposition,  its  study  is  made  more  clear  by  turning  to  and  determining 
the  nature  of  its  logical  basis,  and  proceeding  from  that  as  a  fixed  point. 
While  it  is  true  that  pathology  is  by  no  means  an  exact  science,  for  the 
reason  that  its  mother  science  "  biology  "  has  not  yet  achieved  that  posi- 
tion, it  is  indubitable  that  year  by  year  it  increases  in  the  measure  of 
its  exactitude.  It  is  relatively  a  speculative  science  Avhen  compared 
with  such  a  science  as  chemistry,  which  begins  with  an  approximately 
fixed  unit,  the  atom,  and  has,  therefore,  a  corresponding  stability  of 
superstructure.  A  true,  exact  science,  as  mathematics,  begins  with 
a  fixed  and  unchangeable  unit,  and  is  therefore  absolute. 

The  unit  of  the  physiologist,  and  consequently  of  the  pathologist,  is 
a  complexity  in  itself;  it  is  a  substance  called  protoplasm,  of  which  our 
knowledge  is  imperfect  and  relative  ;  it  follows,  therefore,  that  sciences 
based  upon  such  a  unit  will  be  susceptible  to  changes  and  alterations  until 
the  knowledge  of  the  accepted  unit  is  as  complete  as  the  knowledge  the 
mathematician  has  of  his  unit. 

A  contemporary  philosopher  has  said  that  the  standing  disgrace  of 
the  science  of  chemistry  is  that  it  has  not  yet  given  an  analysis  of 
protoplasm.  Protoplasm,  so  far  as  present  knowledge  permits  a  state- 
ment, is  a  viscid  substance,  which  under  certain  conditions  exhibits  a 
sequence  of  phenomena  which  the  physiologist  calls  life.  Its  chemical 
composition  is  very  imperfectly  known ;  indeed,  the  only  means 
available  for  its  chemical  analysis  are  such  as  destroy  the  identity 
of  the  substance.  More  than  this,  a  subtle  change  occurs  with  the 
cessation  of  vital  activity ;  so  that  in  all  probability  an  analysis  of 
dead  protoplasm  would  not  represent  the  composition  of  vital  pro- 
toplasm. As  set  forth  by  O.  Hertwig,^  "  we  must  regard  protoplasm 
as  a  morphological,  not  a  chemical  conception;"  "it  is  not  a  single 
chemical  substance,  complex  in  composition,  but  is  composed  of  a 
large  number  of  different  chemical  substances  which  we  have  to  pict- 
ure to  ourselves  as  most  minute  particles  united  together  to  form  a 
wonderfully  complex  structure."  "  Protoplasm  cannot  be  placed  under 
different  conditions  without  ceasing  to  be  protoplasm,  for  its  essential 
properties  in  which  life  manifests  itself  depend  upon  a  fixed  organiza- 

1  The  Cell,  1895. 


BASIS  OF  PATHOLOGY.  19 

tion."  '  Huxley  has  well  termed  the  substance  "  the  physical  Ijasis  of 
life."  The  nearest  approach  to  a  chemical  conception  of  the  substance 
is  that  it  is  a  collection  of  proteids  ;  and  of  these  substances  our  knowl- 
edge is  very  imperfect.  They  consist  of  carbon,  hydrogen,  oxygen, 
and  nitrogen,  combined  with  sulphur  and  phosphorus  in  enormous  mole- 
cules. It  is  known  certainly,  however,  that  protoplasm  does  not  behave 
as  a  fixed  chemical  substance. 

As  studied  by  the  physiologist  and  pathologist,  observations  as  to  its 
properties  are  made  in  defined  masses  of  protoplasm,  which  exhibit  the 
sum  of  phenomena  called  life.  A  simple  mass  of  protoplasm  is  studied  to 
determine,  as  far  as  possible,  the  ultimate  phenomena  relating  to  vitality. 
For  this  purpose  an  amoeba,  the  anatomical  equivalent  of  a  white  blood- 
corpuscle,  is  placed  under  conditions  which  permit  of  close  and  con- 
tinued observation  and  where  the  condition  of  its  environment  may  be 
altered  to  study  the  effects  of  such  alterations  upon  the  vital  processes 
of  the  cell.  The  study  of  collections  of  cells  is  a  secondary  pursuit. 
While,  as  has  been  stated,  protoplasm,  or  contemporary  knowledge  of 
it,  is  the  basis  of  the  sciences  of  biology  and  pathology,  the  actual  unit 
of  the  sciences  is  the  cell.  All  reasoning  proceeds  from  this  basis,  that 
the  ultimate  phenomena  of  life  are  expressed  in  cell-life,  so  that  the 
properties  and  functions  found  associated  with  cells  are  the  underlying 
data  of  pathology. 

If  a  drop  of  water  be  taken  from  the  sides  or  bottom  of  an  aquarium, 
placed  on  a  slide  and  covered  with  a  cover-glass,  and  then  placed  under 
a  microscope  with,  first,  a  ^  "  objective,  there  will  be  noted  at  some 
portion  of  the  fluid  a  small  transparent  mass  having  the  appearance  of 
a  colorless  fragment  of  jelly  ;  this  is  an  amoeba.  The  outline  of  the  mass 
may  have  almost  any  form.  At  some  portion  there  will  be  a  defined 
and  easily  distinguished  spot,  the  nucleus ;  at  another  point  a  vesicle 
is  seen  ;  the  body  of  the  amoeba  appears  to  con- 
tain numbers  of  fine  granules.  The  nucleus  ap- 
pears more  markedly  granular  than  the  body  of  the 
amoeba.  If  kept  under  observation,  the  amoeba  will 
be  seen  to  change  its  outlines  ;  at  one  or  more,  and  it 
may  be  in  several  places  projections  like  blunt  arms 
or  feet  are  seen  to  be  extending  from  the  amoeba  (see 
Fig.  1).  On  account  of  their  a]>])earance  they  are 
called  bv  the  phvsiologist  pseudopodia,  from  j^seudo, 
fiilse,  and  pons,  a  foot-false  feet.  These  changes  of  ''amTbl  ■ 'i^rpseu." 
form  are  much  varied  (Fig.  2).  The  cell  has,  there-  podia;  r,  vesicle:  n, 
fore,  the  property  of  altering  its  form — /.  e.,  it  has 
contractility.     If  the  temperature  of  the  slide  be  raised,  the  movements 

1  The  Cell,  1895. 


20 


GENERAL  PRINCIPLES. 


of  the  cell  become  more  rapid,  and  if  raised  to  a  temperature  of  55°  C. 
the  cell  contracts  in  a  round  lump  ;  it  responds  to  stimuli,  and  has  there- 
fore the  property  of  irritability. 


Fig. 


Amceboid  movement  of  a  white  blood-corpuscle  of  man  ;  various  phases  of  movement.    (Klein.) 

When  certain  solid  substances  contained  in  the  water  come  in  con- 
tact with  the  amoeba,  the  latter  is  seen  to  flow  around  and  engulf 
them  ;  as  is  shown  in  Figs.  3  and  4,  where  the  analogue  of  an  amoeba,  a 


Fig.  3. 


Fig.  4. 


Leucocyte  of  a  frog  from  the  neighborhood  of 
a  piece  of  the  lung  of  a  mouse  infected 
with  anthrax,  about  forty-two  hours  after 
the  piece  of  lung  had  been  placed  under  the 
skin  of  the  frog's  back.  The  leucocyte  is 
in  the  act  of  eating  upi  an  anthrax  bacillus. 
(Brunton,  after  MetchnikofF.) 


The  same  leucocyte  a  few  minutes  later,  after 
it  has  completely  enveloped  the  bacillus. 
(Brunton,  after  Metchnikoff.) 


leucocyte,  has  taken  in  bacteria.  After  a  time  the  ingested  body  is  found 
to  have  disappeared ;  it  has  been  digested.  Evidently  the  cell  must 
produce  a  substance  capable  of  dissolving  some  foreign  substances — i.  e.^ 


Fig.  5. 


Forms  assumed  by  a  nucleus  in  dividing :  a,  resting  nucleus ;  ^,  skein-form,  open  stage ;  c,  wreath- 
form;  d,  aster,  or  star-form;  e,  equatorial  stage  of  division;  /.separation  more  advanced; 
<j  and  h,  star  and  wreath  forms  of  daughter-nuclei.  (Reduced  from  Flemming's  drawings  in  the 
Arch.  J.  Mik.  Ariat.) 

it  has  the  function  of  secretion.     More  than  this,  the  amoeba  does  not 
take  in  substances  indiscriminately ;  some  it  rejects. 


CELL-REACTIONS.  21 

If  the  observations  are  continued,  it  will  be  noticed  that  changes 
occur  in  the  nucleus  of  the  cell.  A  series  of  alterations  in  its  figure 
are  noted,  as  shown  in  Fig.  5.  Two  nuclei  are  formed,  and  soon  the 
bodv  of  the  cell  divides  and  two  cells  aj^pear — the  amteba  has  repro- 
duced itself.  This  primitive  cell  has,  therefore,  the  properties  of  irrita- 
bility, contractility,  secretion  and  excretion  (as  will  be  seen  in  later 
studies),  and  reproduction  ;  moreover,  it  responds  to  stimuli,  as  seen  on 
warming  the  stage. 

If  the  stage  be  cooled,  the  movements  of  the  protoplasm  are  less- 
ened, and  when  foreign  substances  come  in  contact  with  the  cell  it  fails 
to  encompass  them — its  irritability  and  contractility  are  lessened. 

It  is  nc>ted  that  some  simple  cells  are  attracted  and  stimulated  by 
light ;  others  are  repelled  by  it. 

If  a  mild  induction  (interrupted)  current  be  passed  through  the  water 
in  which  the  amoeba  is,^  the  movements  of  the  cell  are  checked  ;  if  a 
strong  current  be  passed,  the  cell  contracts  sharply.  If  a  galvanic  (con- 
stant) current  be  passed,  movement  at  first  ceases,  but  pseudopodia  are 
extruded  toward  the  cathode  and  the  cell  crawls  toward  that  pole. 

The  cell  responds  to  mechanical  stimuli,  such  as  violent  shaking,  by 
contraction.- 

If  substances  such  as  ether  or  chloroform  are  added  to  the  fluid,  the 
irritability  of  the  cell  is  so  lessened  that  it  does  not  respond  to  stimuli. 

If  the  supply  of  oxygen  be  cut  off,  or  if  carbon  dioxid  be  admitted 
to  the  fluid,  movement  ceases  and  the  cell  remains  contracted. 

These  examples  serve  to  illustrate  that  protoplasm  responds  to 
stimuli  of  physical  and  chemical  nature,  and  that  its  functions  may  be 
altered  by  substances  which  are  brought  in  contact  with  it.  Upon  these 
facts  depends  the  practice  of  therapeutics. 

A  living  organism,  it  will  be  seen,  has  a  certain  degree  of  action 
and  function.  The  general  average  of  its  action  and  function  is  spoken 
of  as  a  condition  of  health.  "When,  from  any  cause,  the  functions  are 
raised  or  lowered  from  the  general  average,  a  condition  of  disease  exists. 

Stimulation. — Certain  agencies  applied  to  the  cell  increase  its  ac- 
tivity ;  this  is  called  stimulation.  The  movements  of  the  cell  become 
more  rapid,  food-particles  are  taken  in  more  rapidly  and  disappear  more 
quickly ;  irritability,  contractility,  and  secretion  are  increased.  The 
cell  subdivides,  or  reproduces  more  quickly.  Increase  the  stimulation, 
and  the  vital  activity  becomes  fretful ;  in  some  cases  cell-division  is 
incomplete — the  nucleus  divides,  but  not  the  cell-body.  Increase  the 
stimulation  beyond  this  degree,  and  the  wearied  cell  ceases  its  move- 
ments— refuses  to  respond  ;  is  paralyzed  by  overwork. 

Sedation. — If  the  conditions  be  reversed ;  if,  instead  of  applying  a 
1  O.  Hertwis,  The  Cell.  '•'  Ibkl. 


22  GENERAL  PRINCIPLES. 

stimulus  to  the  cell,  an  opposite  influence  be  introduced,  the  phenomena 
are  reversed. 

If  the  temperature  be  reduced,  the  movements  of  the  cell  become 
sluggish ;  the  body  changes  its  form  more  slowly  and  less  extensively — 
i.  e.,  contractility  is  lessened ;  particles  taken  into  the  cell  remain  appar- 
ently unchanged  ;  irritability,  secretion,  and  excretion  are  lessened  ;  and, 
furthermore,  reproduction  does  not  occur  nearly  so  rapidly — that  is,  the 
cell  in  contact  with  sedative  influences  has  all  of  its  activities  lessened. 

There  are  two  great  classes  of  influences,  then,  wdiich  aifect  the  vi- 
tality of  cells  :  stimulation,  which,  if  continued  long  enough,  leads  to 
death  through  overwork  ;  and  sedation,  which,  if  continued,  paralyzes 
all  of  the  energies  of  the  cell — it  is  starved  to  death. 

Every  cell  has  a  range  of  resistance  to  these  influences  which  tend 
to  destroy  it,  which  is  fitly  termed  the  resistance  of  vitality.  Disease 
itself  is  some  alteration  in  any  one  or  more  of  these  several  cell-proper- 
ties, of  irritability,  contractility,  growth,  secretion,  maintenance,  or 
reproduction.  If  any  one  of  these  properties  is  not  exhibited,  it  is 
said  that  the  cell  is  diseased. 

If  a  brood  of  cells  derived  from  one  parent  be  examined,  some 
will  be  seen  to  grow  more  rapidly  than  others,  their  movements  are 
more  rapid  and  they  reproduce  more  quickly ;  others  have  sluggish 
functions  and  movements. 

The  cell  lives  its  cycle  and  reproduces,  and  the  parent  is  no  more, 
the  life  being  continued  in  the  oflPspring. 

The  life  and  properties  of  this  small  mass  of  protoplasm  represent 
in  miniature  the  primitive  functions  and  life  of  the  highest  animals. 

The  contractility  is  represented  in  the  motive  apparatus  of  the  higher 
animals. 

The  reception,  engulfing,  and  dissolving,  or  casting  out,  bodies  with 
which  the  amoeba  is  brought  in  contact  correspond  in  the  higher  animals 
with  the  digestive  apparatus  and  process  and  the  excretory  function. 

The  highly  evolved  irritability  is  represented  in  the  nervous  system 
of  the  higher  animals. 

The  movements  occurring  in  and  about  the  vacuole  are  the  progenitors 
of  the  circulatory  apparatus  and  all  of  its  adjunct  organs. 

If  the  irritability  of  a  simple  cell  be  increased  or  diminished,  it 
corresponds  with  a  disease  of  the  nervous  system,  and  so  with  the  other 
functions. 

It  is  essential  to  the  life  of  a  cell  that  the  means  be  aflbrded  it  of 
continuing  the  activities  called  life.  First,  it  must  receive  a  proper 
food-supply,  which  includes  an  abundance  of  water  and  such  solid  sub- 
stances, either  contained  in  the  water  or  dissolved  in  it,  as  are  necessary 
to  replace  loss  of  substance  in  the  cell ;  these  are  albuminous  substances, 


CELL-FUNCTIONS.  23 

to  replace  used-up  nitrog;euous  matters;  carbohydrates  and  hydrocarbons, 
to  replace  the  everchanging  proportions  of  carbon  and  hydrogen  of  living 
matter  ;  and,  lastly,  the  supply  of  oxygen  must  be  sufficient.  The  cell 
must  be  maintained  at  a  proper  temperature.  Its  waste-products  must 
be  removed.  If  any  of  these  conditions  be  interfered  with,  vitality  is 
depressed.  The  most  certain  cause  of  prompt  death  is  an  absence  of 
oxygen.     Cell-life  is  maintained  largely  by  a  process  of  oxidation. 

In  the  performance  of  any  vital  act  chemical  change  is  inevitable ; 
that  is,  some  portion  or  amount  of  protoplasm  undergoes  chemical 
alteration  ;  the  substances  brought  as  food  by  the  circulating  fluid  are 
built  into  cell-substance  to  replace  those  which  are  lost ;  the  setting  free 
of  chemical  energy  by  the  process  of  protoplasm  breaking  down  into 
simpler  bodies  is  manifested  in  the  production  of  heat. 

The  oxygen  about  the  cell  combines  with  the  products  of  cell- 
activity,  and  changes  them  into  substances  from  which  the  cell  frees 
itself — the  waste,  the  products  of  its  activity,  is  removed.  The  products 
of  cell-activity  are  largely  acid  in  reaction,  and  the  increase  of  acid  in 
protoplasm  lessens  its  affinity  for  oxygen  ;  hence  in  an  overworked  cell 
oxidation  is  sluggish,  for  the  outer  portions  of  the  cell  have  a  lessened 
alkalinity. 

It  is  important  that  a  familiarity  with  cell-properties  be  obtained, 
because  the  functions  of  any  body  are  made  up  of  the  functions  of  its 
cells.  As  before  stated,  in  the  more  highly  evolved  animals  special  col- 
lections of  cells  and  special  areas  are  set  aside  to  perform  the  functions 
in  which  the  entire  substance  of  an  amceba  participates. 

Certain  collections  of  cells  are  found  in  which  one  function  is  active, 
the  others  in  abeyance  ;  thus,  large  colonies  of  cells  exist  in  which 
contractility  is  the  dominant  property  noted  ;  these  are  muscle-cells. 
Others  have  but  the  property  of  irritability ;  these  are  nerve-cells. 
Still  others  develop  peculiar  chemical  functions,  and  become  glandular 
or  secretory  cells.  Such  collections  of  cells  are  known  as  tissues.  These 
special  cell-colonies  or  tissues  are  built  together  into  defined  masses  for 
the  performance  of  their  specialized  functions.  In  the  development  of 
these  masses,  means  of  holding  and  maintaining  the  cells  in  definite 
mass-forms  and  provisions  for  their  food-supply  and  waste-removing 
apparatus  are  provided  in  what  are  called  the  connective  tissues,  binding 
the  cells  in  definite  forms  and  transmitting  their  vascular  supply  (food- 
and  waste-carrier).  When  thus  bound  together  the  tissues  are  said  to 
form  organs. 

In  studying  disorders  which  may  affi'ct  any  one  or  more  organs,  or 
their  parts,  the  problem  becomes  apparently  complex,  but  it  ultimately 
resolves  itself  into  a  study  of  the  disorders  of  the  cells  of  the  part.  A 
disease  may  only  be  evident  through   disorder  of  some   function,   for 


24  GENERAL  PRINCIPLES. 

when  the  tissue  affected  is  studied  no  evidence  of  disease  is  seen  even 
under  the  highest  powers  of  the  microscope. 

Another  class  of  diseases  will  exhibit  changes  which  have  occurred 
in  the  anatomy  of  the  part,  which  prompts  the  classification  of  diseases 
into  functional  and  structural.  Functional  diseases  are  those  which 
exhibit  no  demonstrable  alteration  in  the  anatomy  of  a  part.  Struc- 
tural diseases  are  those  in  which  the  anatomical  structure  of  a  part  is 
altered. 

Definite  anatomical  changes  have  been  found  constantly  associated 
with  a  more  or  less  constant  group  of  symptoms.  The  changes  are 
spoken  of  as  the  morbid  anatomy  of  a  disease. 

The  pathology  of  any  disease  means  the  morbid  physiology  through 
which  these  anatomical  changes  are  brought  about.  In  the  absence  of 
direct  anatomical  examination  of  any  organ  a  knowledge  that  it  is  not 
performing  its  work  properly  and  that  its  functions  are  disordered  is 
obtained  by  noting  whatever  phenomena  are  obtainable.  These  are,  in 
part,  what  the  observer  may  note  through  the  use  of  his  senses,  and  by 
utilizing  the  resources  of  physics  and  chemistry.  Knowledge  gained  by 
such  means  is  called  the  objective  evidence  of  disease.  Certain  facts 
are  elicited  by  questioning  a  patient  as  to  altered  sensations,  the  nature 
and  situations  of  pain,  etc. ;  these  are  known  as  the  subjective  evidences 
of  disease. 

The  study  of  symptoms  elicited  from  the  patient  by  examination  and 
noted  in  his  physical  appearance  is  known  as  Semeiology,  from  semeion, 
a  mark  or  sign. 

A  special  study  is  made  of  the  influences  and  conditions  through 
which  the  functions  of  the  body  are  disordered  ;  this  is  known  as  Eti- 
ology. 

It  is  noted  that  diseases  presenting  a  certain  or  an  uncertain  morbid 
anatomy  and  a  constant  course  of  symptoms  have  from  their  beginning 
to  ending  tolerably  constant  phenomena ;  they  have  each  a  natural  his- 
tory ;  this  is  called  the  Clinical  History  of  a  Disease. 

There  are  symptoms  which  are  common  to  many  disease-conditions, 
and  others  which  are  associated  with  but  some  one  distinctive  morbid 
state ;  different  diseases  may  exhibit  several  symptoms  in  common,  and 
some  few,  which  serve  to  distinguish  the  one  from  the  other.  The  study 
which  deals  with  that  discrimination  between  groups  of  symptoms 
which  characterize  distinct  diseases  is  called  Diagnosis,  from  Greek  dia, 
through,  and  gignosJco,  I  know.  It  embraces  a  consideration  of  all  of 
those  phenomena  which  indicate  the  exact  disease-state  present. 

In  the  study  of  the  clinical  history  of  diseases  it  is  observed  that 
while  each  disease  has  a  more  or  less  well-defined  natural  history,  they 
vary  as  to  the  course  followed  in  individuals  and  the  final  outcome.     It 


STUDY  OF  DISEASE.  25 

is  observed  that  there  are  signs  and  symptoms  which  are  followed  by 
good  or  ill  results,  as  the  case  may  be.  By  these  signs  and  symptoms 
it  mav  be  foretold  with  some  degree  of  assurance  what  will  be  the  prob- 
able outcome  of  the  disease.  The  branch  of  inquiry  dealing  with  this 
aspect  of  disease-study  is  known  as  Prognosis,  from  pro,  before,  and 
gifftiosko. 

It  is  found  that  agencies  described  in  the  succeeding  chapter  as  dis- 
ease-causes affect  tissues  and  organs  in  such  manner  that  their  phys- 
iology is  altered  and  changes  occur  in  their  anatomical  structure.  The 
occurrence  of  these  disordered  functions  and  structures  is  attended  by 
signs  and  symptoms  which  indicate  their  presence.  The  study  of  these 
particular  features  of  disease  is  called  Pathogenesis ;  while  it  might  be 
inferred  from  the  etymology  of  this  word  {jjathos,  disease,  and  gennao, 
I  produce)  that  it  was  but  another  name  for  etiology,  it  covers  a  wider 
field. 

Recognizing  by  the  presence  of  signs  and  symptoms  that  the  phys- 
iology of  one  or  more  organs  is  disordered,  and  that  probably  changes 
of  structure  have  occurred,  the  great  problem  of  the  healing  art  is  to 
apply  such  measures  and  agencies  as  shall  restore  the  tissues  or  organs 
to  their  normal  condition  and  function.  This  branch  of  medicine  is 
known  as  Therapeutics,  from  iherapeuein,  to  take  care  of,  to  heal. 

Centuries  of  observation  have  shown  that  there  are  numerous 
agencies  and  substances  which  are  capable  of  producing  alterations  in 
the  action  or  physiology  of  organs  ;  these  agencies  and  substances  are 
included  in  what  is  called  the  Materia  Medica — the  materials  of 
medicine. 

An  increasing  importance  attaches  to  that  method  of  studying  the 
feature  of  the  healing  art  which  begins  with  a  knowledge  of  the  exact 
chemical  composition  of  each  substance  used,  and  traces  with  the  utmost 
care  the  effects  of  these  substances  upon  the  chemical  composition  and 
the  functions  of  organs,  and  how  these  effects  may  be  utilized  in  com- 
bating disease  ;  this  study  is  called  Pharmacology. 

The  method  of  treating  disease  which  begins  with  an  exact  knowl- 
edge of  the  causes  of  diseases,  the  significance  of  their  symptoms,  and 
their  clinical  history,  together  with  the  nature  of  the  alterations  of  the 
physiology  of  organs  which  give  rise  to  symptoms,  and  the  reasons  and 
nature  of  the  anatomical  changes  which  result  from  this  altered  phys- 
iology, and  embracing  an  exact  knowledge  of  the  effects  of  agents  in 
the  materia  medica,  which  properties  are  to  be  utilized  in  such  manner 
that  the  causes,  phenomena,  and  results  of  disease  are  neutralized,  is 
called  Rational  Therapeutics. 

Such  precise  familiarity  with  the  nature  of  disease,  and,  upon  the 
other  hand,  of  the  action  of  therapeutic  agents,  is  not  a  possession  of 


26  GENERAL  PRINCIPLES. 

medicine  ;  although  it  had  been  noted  and  confirmed  by  years  of  obser- 
vation that  the  application  or  administration  of  certain  agents  is 
followed  by  a  disappearance  of  symptoms  and  of  the  evidences  of 
disease ;  the  type  of  treatment  pursued  upon  this  basis  is  called 
Empirical  Therapeutics. 

When  it  is  observed  that  patients  exhibit  groups  of  symptoms 
which  appear  as  constant  features  of  clinical  histories,  which  are  alike, 
and  it  is  further  noted  that  the  causes  giving  rise  to  these  symptoms 
are  identical,  and  when,  furthermore,  examination  shows  the  same 
organs  to  be  affected  in  one  manner,  a  distinctive  name  is  applied 
to  describe  the  condition  ;  it  is  known,  or  designated,  as  some  distinct 
disease.  For  example,  a  number  of  persons  who  drink  water  from  a 
common  source  are,  one  by  one,  affected  by  diarrhoea  and  a  gradually 
rising  temperature  of  the  body,  followed  by  evidences  of  debility  and 
general  poisoning,  which  symptoms  subside  after  about  three  weeks  : 
the  patients  are  said  to  have  the  distinctive  disease,  typhoid  fever. 

It  is  preferable,  when  it  can  be  done,  to  name  a  disease  to  accord 
with  its  anatomical  and  physiological  features.  For  example,  chem- 
ical examination  of  a  patient's  urine  shows  it  to  contain  albumin ;  ex- 
amined under  a  microscope  it  shows  what  are  called  tube-casts ;  at  a  later 
period,  dropsy  or  cedemas  (which  see)  appear,  and  the  patient  exhibits 
evidences  of  poisoning,  and  later  dies.  On  examining  the  tissues  of 
the  body  it  is  found  that  the  secretory  or  parenchymatous  portions  of 
the  kidney  are  destroyed ;  the  disease  is  designated  then  as  parenchy- 
matous nephritis.  This  word  is  derived  from  parenchuma,  the  sub- 
stance of  organs,  and  nephros,  a  kidney,  the  termination  itis  signifying 
inflammation.  This  suffix  always  means  inflammation  ;  for  example, 
inflammation  of  a  joint  is  known  as  arthritis,  from  arthron,  a  joint; 
pulpitis,  inflammation  of  a  tooth-pulp,  and  so  on. 

Some  disorders  can  only  be  named  from  a  symptom,  as  neuralgia, 
from  neuron,  a  nerve,  and  cdgos,  pain.  The  suffix  algos  always  signi- 
fies pain  in  the  organ  or  tissue  named  in  the  stem  of  the  word,  as 
odontalgia,  stem  odont,  from  the  Greek  odous,  a  tooth. 

Pains  of  a  rheumatic  character  are  described  by  the  suffix  dynia, 
from  odune,  -pain,  as  in  pleurodynia,  from  pleura,  the  side,  and  odune, 
pain. 

Pains  of  gouty  origin  are  named  by  the  suffix  agra,  a  seizure,  as 
podagra,  from  jMUti,  poda,  a  foot,  and  agra,  a  seizure,  M^hich  describes 
gout  of  the  foot.  Odontagra  would  be  the  name  applied  to  gouty  pain 
in  or  about  a  tooth. 

B'-fore  the  diseases  or  disorders  of  any  tissue  or  organ  can  be 
studied  intelligently  it  is  necessary  that  tlie  student  be  familiar  with 
the  anatomy  of  the  part,  as  revealed  by  the  scalpel,  or  macroscopic 


STUDY  OF  DISEASE.  27 

anatomy,  and  as  revealed  by  the  microscope,  the  histology  of  the  organ 
and  the  tissues  of  which  it  is  composed,  or  its  microscopic  anatomy. 
It  is  necessary  that  a  knowledge  of  its  physiology  be  acquired;  the 
nature  of  the  work  performed,  how  and  by  what  performed.  The  nature 
of  the  chemical  changes  which  occur  in  tissues  and  organs  should  also 
be  known  ;  and,  finally,  the  mode  of  development,  the  embryology  of 
the  tissues  and  organs,  should  be  studied. 

It  is  customary — in  fact,  almost  necessary — that  a  disease  be  studied 
systematically  in  all  of  its  bearings.  First,  What  is  the  definition  of 
the  disease  ?  Secondly,  How  has  it  been  studied  in  the  past  ? — i.  e.,  What 
is  its  history  ?  A  study  of  etiology,  or  the  causes  of  the  disease,  follows. 
Next,  What  is  its  semeiology  ? — L  e.,  What  are  its  symptoms  ?  Next  an 
inquiry  is  directed  to  the  nature  of  the  alterations  in  the  physiology  of 
the  parts  involved,  and  what  changes  of  structure  occur — I.  e.,  a  study  of 
the  pathology  and  morbid  anatomy  of  the  disease.  The  clinical  history 
is  next  taken  up,  and  followed  by  a  consideration  of  its  diagnosis ;  its 
prognosis  or  probable  outcome  is  next  adjudged ;  and,  finally,  the  ques- 
tions of  How  shall  the  disease  be  combated?  What  shall  be  its 
treatment  ? 

With  an  increasing  knowledge  of  the  pathogenesis  of  diseases,  it  is 
but  natural  that  it  should  lead  to  the  study  of  the  rational  methods  of 
preventing  disease — i.  e.,  their  prophylaxis  (Greek  jt>?-o,  before  ;  phidasso, 
I  preserve  ;  and  phulax,  a  guard).  It  is  manifestly  preferable  to  prevent 
disease  than  to  permit  its  onset  and  treat  the  condition.  Before  intelli- 
gent efforts  can  be  directed  toward  the  prevention  of  disease  a  knowl- 
edge of  disease-causes  is  necessary,  for  the  prophylaxis  of  any  disease 
is  the  destruction  or  neutralizing  of  its  causes  before  they  have  oppor- 
tunity to  act. 


CHAPTER   II. 
CAUSES  OF  DISEASE,   GENERAL  AND  LOCAL. 

A  DISEASE-CAUSE  may  be  defined  as  any  influence  of  whatsoever 
nature  which  is  capable  of  disturbing  the  nutritive  balance  of  any  por- 
tion of  the  body.  That  branch  of  study  which  deals  with  the  causes  of 
disease  is  called  Etiology,  from  Greek  aetios,  causes,  and  logos. 

Every  living  organism  and  all  parts  of  the  more  highly  organized 
animals  possess  the  power  of  maintaining  a  nutritive  balance  despite 
changes  in  their  surroundings ;  moreover,  they  persist  as  living  bodies 
though  assailed  by  forces  which  tend  to  disturb  the  complexus  of  j^he- 
nomena  called  life,  even  though  these  forces  do  frequently  bring  about 
modifications  in  their  capacity  for  work.  All  of  these  threatening  influ- 
ences may  be  regarded  as  disease-causes,  and  an  examination  of  the 
forces  which  tend  to  disturb  the  natural  working  of  portions  of  the  body 
will  show  them  to  be  very  numerous ;  but,  as  will  be  seen  later,  they 
may  be  grouped  under  a  few  convenient  headings. 

This  study  deals  with  the  forces  and  influences  which  act  upon  the 
body  from  the  outside ;  they  are  called  the  extrinsic  causes  of  disease. 

The  evolutionist  points  out  that  all  animals  of  a  species  are  not 
equally  resistant  to  the  same  causes  acting  upon  all,  for  if  a  number  of 
animals  be  jjlaced  under  identical  conditions,  some  will  be  more  strongly 
aifected  than  others  ;  some  are,  therefore,  said  to  have  a  greater  inherent 
resistance  than  others.  The  reason  for  this  difference  in  resistive  power 
is  spoken  of  as  intrinsic ;  the  causes  of  the  lessened  resistance,  as  the 
intrinsic  causes  of  disease.  The  cause  of  the  condition  may  be  sought 
for  in  all  three  of  the  factors  which  go  to  make  up  the  analysis  of  cell- 
life,  chemical,  physiological,  and  anatomical ;  although  it  is  at  times 
difficult  or  even  impossible  to  determine  exactly  Avhich  element  is  at 
fault.  An  examination  of  the  part  may  reveal  some  structural  change, 
some  alteration  of  its  anatomical  forms ;  or,  again,  it  can  only  be  said 
that  the  part  does  not  functionate  properly,  or  it  may  be  that  the  evi- 
dence of  disorder  is  a  persistent  deficiency  in  the  chemical  nature  of 
cell-products.  It  is  impossible  to  separate  the  physiological  from  the 
chemical  side  of  this  problem. 

The  only  present,  tangible  conditions  which  can  be  regarded  as  purely 
intrinsic  disease-causes  are  changes  in  anatomical  structure.  Changes 
or  conditions  which  alter  the  physiological  action  of  any  part  of  the 

28 


PREDISPOSING   CA  USES  OF  DISEASE.  29 

body,  so  that  it  succumbs  to  iuflucnccs  which  uornuilly  it  sliould  resist, 
are  called  predisposing  causes  of  disease.  It  is  evident  that  what  are 
termed  intrinsic  causes  are  all  predispositions.  It  is  customary,  there- 
fore, to  divide  the  study  of  disease-causes  under  two  heads  :  first,  all 
of  those  conditions  which  render  any  part  more  susceptible  to  the  ac- 
tion of  inimical  forces,  or  the  predisposing  causes  of  disease  ;  secondly, 
those  to  whose  action  upon  the  body  disease  is  directly  due,  or  the  ex- 
citing causes  of  disease.  A  predisposing  cause  may  be  intrinsic  or  ex- 
trinsic, which  is  also  true  of  the  exciting  causes,  so  that  we  may  divide 
both  the  predisposing  and  the  exciting  causes  into  intrinsic  and  extrinsic. 

Predisposing  Causes  of  Disease. 

Life  in  itself  is  a  persistence  of  energy  in  a  chemical  substance 
of  unknown  nature,  against  forces  which  tend  to  disturb  its  chemical 
integrity,  and,  as  a  consequence,  its  energy  or  its  structure.  Any 
forces  or  influences  acting  from  within  or  Avithout  an  organized  mass 
of  the  substance,  which  lessen  its  resistance  to  those  forces,  predispose  to 
its  destruction.  Applied  on  a  large  scale,  there  comes  the  study  of 
the  influences  which  tend  to  lessen  the  resistive  forces  of  the  body. 
The  first  of  these  is  naturally  an  alteration  of  anatomical  structure,  for 
if  there  is  a  standard  of  structure  best  adapted  to  meeting  and  over- 
coming conditions  to  which  living  bodies  are  subjected,  any  variation  in 
this  standard  is  necessarily  followed  by  lessened  resistance. 

These  alterations  of  structure  may  be  congenital  or  acquired  ;  they 
may  be  due  to  a  faulty  development  which  may  be  traced  to  the  ovum 
or  the  spermatozoa  of  the  parent,  or  they  may  arise  after  birth  and  a 
period  of  apparently  normal  development.  The  abnormalities  may  be 
macroscopic,  so  evident  that  they  are  seen  at  a  glance  to  be  malforma- 
tions ;  or  they  may  be  microscopic,  requiring  special  preparation  of  por- 
tions of  organs  to  demonstrate  their  existence. 

Sex  as  an  Intrinsic  Predisposing-  Cause. — In  this  connection  the 
influence  of  sex  upon  predisposition  to  disease  must  be  considered. 
While  the  general  resistive  jiower  of  the  bodies  of  both  sexes  may  be 
regarded  as  practically  equal  under  similar  conditions,  yet  the  anatom- 
ical structures  and  physiology  of  each  sex  have  an  influence  upon  predis- 
position to  certain  diseases.  Aside  from  the  diseases  peculiar  to  sex, 
on  account  of  their  peculiar  organs,  each  sex  exhibits  predisposi- 
tions to  diseases  which  the  other  sex  escapes  ;  for  many  of  these  the 
habits  of  life  furnish  an  explanation,  for  others  an  explanation  is  not 
available.  For  example,  while  women  are  predisposed  to  functional 
and  emotional  disturbances  of  the  nervous  system,  such  as  hysteria,  they 
are  almost  exempt  from  such  structural  nervous  diseases  as  locomotor 
ataxia  and  general  sclerosis. 


30  CAUSES  OF  DISEASE,   GENERAL  AND  LOCAL. 

Men  may  become  anaemic  from  a  variety  of  causes ;  but  young  girls 
become  chlorotic,  a  disease-type  which  rarely  affects  the  male. 

Women  are  aifected  by  diseases  of  internal  secretory  glands,  as  the 
thyroid,  and  escape  aifections  of  others,  as  of  tlie  suprarenal  capsules. 

Ag-e  as  an  Intrinsic  Predisposing  Cause. — The  cycle  of  life  of  an 
organized  being  comprises  an  intra-  and  an  extra-uterine  development 
until  maturity  is  attained  ;  while  increment  exceeds  excrement,  growth 
is  in  progress.  This  is  followed  by  a  period  in  which  increment  and 
excrement  are  balanced  ;  waste  and  repair  are  equal ;  this  is  the  period 
of  maintenance.  Succeeding  is  the  period  of  decadence,  when  the 
tissues  of  the  body  undergo  gradual  changes  leading  to  exhaustion  ;  the 
vital  forces  are  lessened ;  the  power  of  repair  does  not  equal  the  waste 
occurring  throughout  the  body.  In  each  of  these  periods  there  is 
exhibited  a  predisposition  to  certain  diseases. 

Intra-uterine  causes  acting  produce  abnormalities  of  structure — a 
general  intrinsic  predisposition.  During  the  first  period  of  extra- 
uterine growth  there  is  a  predisposition  to  gastro-intestinal  disorders 
and  reflex  disturbances  of  the  nervous  system.  At  a  later  period  there 
is  a  predisposition  exhibited  to  the  eruptive  fevers,  scarlatina,  rubeola, 
varicella,  and  variola,  and  also  to  diphtheria — diseases  which  are 
called  the  diseases  of  childhood.  Later,  in  the  period  of  adolescence, 
other  pix'dispositions  occur  in  young  girls,  notably  chlorosis.  Later 
come  the  diseases  of  early  maturity,  such  as  typhoid  fever.  Diseases 
characterized  by  degenerative  changes  in  the  tissues  and  organs  are  so 
distinctive  accompaniments  of  senility  that  they  are  called  the  diseases 
of  old  age. 

Temperament  as  an  Intrinsic  Predisposing  Cause. — The  influence 
of  temperament  upon  disease  is  frequently  overlooked.  Accepting  as  a 
basis  the  classification  of  Hippocrates  as  indicating  the  four  classes  of 
temperament,  it  may  be  said  that  persons  of  the  sanguine  tempera- 
ment have  a  pi'edisposition  to  acute  pulmonary  and  cardiac  diseases, 
together  with  those  of  the  bloodvessels ;  inflammatory  disorders  are 
disposed  to  run  a  riotous  course.  Those  of  the  nervous  temperament, 
to  disorders  of  the  corresponding  anatomical  system,  particularly  func- 
tional disorders.  Those  of  the  bilious  temperament  exhibit  a  predis- 
position to  affections  of  the  liver.  Those  of  the  lymphatic  temperament 
have  a  predisposition  to  passive  congestions.  The  truth  of  these  rules 
may  be  more  apparent  than  real,  for  close  scientific  studies  relative  to  the 
subject  of  temperament  are  extremely  meagre. 

Heredity. — Certain  diseases  exhibit  a  predisposition  to  descend  from 
parent  to  child  ;  as,  for  example,  gout,  rheumatism,  syphilis,  the  tuber- 
cular diathesis,  epilepsy,  etc.  The  mode  of  transmission  is  in  all  prob- 
ability the  inheritance  of  a  type  of  tissue ;  a  tissue  anatomy  and  phys- 


IMMUNITY.  31 

iology  which  permit  the  more  ready  action  of  the  exciting  causes  of 
these  maladies.  These  cases  might  perliai)s  be  fitly  included  under  the 
head  of  malformations,  though  the  malformations  may  be  undiscover- 
able.  Persons  who  exhibit  this  tendency  to  an  hereditary  disease  such  as 
gout  are  said  to  have  that  diathesis.  The  hereditary  victims  of  such 
diseases  as  syphilis  are  said  to  be  cachectic. 

Existing-  Disease. — The  presence  of  one  disease  may  predispose  to 
others,  as,  for  example,  acute  rheumatism  predisposes  to  organic  dis- 
ease of  the  heart-valves ;  however,  in  this  as  in  many  diseases,  what 
appear  to  be  supplementary  diseases  may  be  but  phases  of  the  same 
disease. 

Previous  Disease. — Frequently  a  part  which  has  once  been  the  seat 
of  disease  is,  when  apparently  recovered,  the  seat  of  the  same  disease 
or  other  disease  at  a  subsequent  period.  Previous  disease  may,  on 
the  contrary,  confer  immunity  from  the  same  disease  in  the  future. 
This  principle  is  of  wide  and  increasing  application  in  medicine. 
Notable  examples  of  this  are  found  in  smallpox  (variola)  and  in  scarlet 
fever  (scarlatina),  and  to  a  less  extent  in  typhoid  fever. 

Extrinsic  Predisposing"  Causes  of  Disease. — Under  this  head  are 
included  all  of  those  conditions  which  cause  a  person  to  fall  a  victim 
to  a  disease  when  exposed  to  its  active  causes.  Cold  and  damp  are 
among  the  conditions  which  act  as  predisposing  causes  of  disease,  as,  for 
example,  to  pneumonia,  rheumatism,  and  a  number  of  inflammatory 
disorders.  Dentists  note  how  cold  and  damp  act  as  predisposing  influ- 
ences in  the  induction  of  pericementitis.  The  reasons  for  this  will 
appear  in  the  discussion  of  hyperaemia. 

Immunity. — When  a  number  of  persons  are  exposed  to  the  active 
causes  of  disease  it  will  be  seen  that  some  succumb  to  the  disease 
immediately  ;  others  are  unaffected — i.  e.,  they  are  immune.  Some  are 
not  affected  no  matter  how  prolonged  the  exposure  ;  others  exhibit  a 
tardy  response  to  the  action  of  the  disease-cause.  The  reasons  for 
these  degrees  of  natural  insusceptibility  are  but  imperfectly  understood. 

Immunity  from  a  particular  disease  may  be  inherited  or  acquired. 
It  may  be  exhibited  toward  only  one  disease.  In  some,  disease  ap- 
pear to  be  influenced  by  sex — as,  for  example,  males  have  a  general 
immunity  from  goitre ;  females,  immunity  from  Addison's  disease. 
Immunity  is  influenced  by  age  in  certain  diseases  ;  for  example,  the 
diseases  of  childhood  are  rare  in  the  elderly  ;  they  do  occur,  however. 
The  degenerative  diseases  of  old  age  are  almost  unknown  in  childhood. 
Race  has  its  influence  ;  the  negro  is  peculiarly  susceptible  to  smalli)0x, 
and  almost  immune  from  malaria. 

Natural  immunity  is  a  very  uncertain  quantity  ;  there  is  no  method 
of  determining  its  duration  without  direct  exposure. 


32  CAUSES  OF  DISEASE,   GENERAL  AND  LOCAL. 

The  most  interesting  and  useful  feature  of  immunity  is  the  possi- 
bility of  its  acquirement  through  natural,  or  its  induction  through 
artificial  means.  It  had  been  noted,  as  long  ago  as  certain  conditions 
were  recognized  as  definite  diseases,  that  those  who  recovered  from 
them  were  rarely  the  subjects  of  the  same  disease  in  the  future,  although 
exposed  to  actively  contagious  influences.  The  classical  example  of 
this  acquired  immunity  is  smallpox.  We  are  indebted  to  Saracen 
medicine,  adopted  or  followed  by  the  Turks  of  Constantinople,  for  the 
early  studies  as  to  artificial  immunity  from  this  disease.  Noting,  no 
doubt,  that  virulent  contagion  was  associated  with  the  pustular  stage 
of  smallpox ;  that  immunity  of  some  persons  did  exist ;  and  that  the 
disease  was  self-protective  :  a  minute  portion  of  the  virus  was  intro- 
duced into  the  bodies  of  healthy  persons.  This  induced  in  most  of 
them  the  disease  in  a  milder  form,  and,  although  the  death-rate  was  con- 
siderable, an  acquired  immunity  was  the  result.  In  1718  Lady  Mary 
Wortley  Montague  introduced  the  practice  into  England,  where  it  met 
Avith  much  opposition  and  limited  adoption.  It  may  be  remarked  that 
the  mortality  of  the  cases  inoculated  is  but  from  3  to  5  per  1000.  In 
1798,  Jenner,  an  English  physician,  applied  the  rustic  knowledge  that 
persons  who  had  been  inoculated  with  the  virus  of  cowpox  were  insus- 
ceptible to  smallpox,  and  became  the  virtual  founder  of  inoculation  by 
attenuated  virus.  This  practice  in  its  later  phases  is  one  of  the  most 
important  developments  of  modern  medicine. 

The  exact  method  through  which  inoculation  brings  about  immunity 
can  at  present  only  be  surmised.  (See  Bacteria  (alexins).)  It  is  impor- 
tant to  remember,  as  illustrated  in  the  principle  of  vaccination,  that 
living  bodies  have  protective  mechanisms  against  disease  which  undergo 
variations  in  degree  of  activity,  and  that  this  activity  is  in  some  cases 
susceptible  of  artificial  alteration. 

Exciting  Causes  op  Disease. 

Under  the  head  of  the  exciting  causes  of  disease  are  included  all  of 
those  variations  in  bodily  and  cellular  environment  which  interfere 
with  the  normal  performance  of  function.  The  conditions  of  cellular 
life  are,  that  cells  must  receive  a  proper  food-supply,  must  have  removed 
the  waste-products  resulting  from  their  life-processes,  and  must  be  main- 
tai>cd  at  a  proper  temperature.  In  a  complex  organ  the  process  of 
nutrition  is  more  complicated,  and  a  greater  number  of  elements  must 
be  studied,  for  not  only  are  the  food-supply  and  waste-removal  relegated 
to  special  structures,  but  a  nervous  element  is  introduced. 

All  of  those  causes  Avhich  relate  to  food-supply,  all  of  the  processes 
which  food  undergoes  while  being  changed  into^  substances  fit  for  cell- 
nutrition,  the  removal  of  waste,  and  also  the  supj)ly  of  oxygen,  may  be 


EXCITING   CAUSES  OF  DISEASE.  33 

grouped  under  the  head  of  abnormal  l)lood-supply.  In  studying  the 
influences  which  are  grouped  under  this  head,  every  stage  through 
which  the  food  passes  in  being  changed  from  albumins,  fats,  and 
starches,  into  material  to  be  utilized  by  cells,  the  composition  of  the 
blood,  its  mode  of  distribution,  its  supply  of  oxygen,  the  removal  of 
waste-substance  from  cells  and  its  elimination  from  the  body,  must 
be  taken  into  consideration. 

Abnormal  Pood-supply. — When  a  man  has  attained  maturity 
waste  equals  repair  in  the  body ;  sufficient  food  is  taken  into  the  body, 
carried  to  the  organs  and  utilized  by  their  cells  to  replace  the  sub- 
stance lost  through  functional  activity,  the  waste-substances  being  oxi- 
dized by  the  oxygen  carried  by  the  red  blood-corpuscles  ;  carbon  clioxid, 
urea,  and  other  waste-substances  are  formed,  which  are  immediately  re- 
moved from  about  the  cells.  Each  cell  is  a  chemical  laboratory  in  min- 
iature, and  any  variation  in  the  nature  of  the  substances  present  pro- 
duces changes  in  the  chemical  interchanges  or  reactions. 

It  is  evident,  therefore,  that  the  study  of  abnormal  food-supply  is  an 
extensive  one,  for  the  cause  of  the  presence  of  improper  pabulum  may 
be  traced  to  any  stage  of  nutrition  from  the  non-reception  of  the  proper 
amount  and  quality  of  food  and  its  imperfect  mastication,  to  faults  con- 
nected with  glandular  secretion  of  the  alimentary  tract,  to  faulty  opera- 
tions while  the  digested  and  absorbed  food-stuffs  are  in  the  portal  system  ; 
next,  to  the  general  character  and  condition  of  the  circulatory  system, 
to  the  time  when  the  pabulum  is  in  the  lymph-spaces.  Any  abnor- 
mality of  function  in  any  one  of  these  particulars  may  be  followed  by 
imperfect  nutrition  of  cells. 

Waste-products  as  Disease-causes. — For  the  normal  performance 
of  cell-function  it  is  quite  as  essential  that  cells  should  have  their  waste- 
products  removed  as  it  is  that  they  should  receive  a  sufficient  supply 
of  pabulum  and  oxygen. 

Waste-products  of  cell-action  are  the  ashes  of  the  vital  fire  ;  are  oxi- 
dized products  of  cell-contents  which  have  a  simpler  chemical  composi- 
tion than  the  pabulum  or  cell-materials  out  of  which  they  are  formed. 
Principal  among  these  products  are  carbon  dioxid  and  the  product  of 
albuminous  waste — urea.  Numerous  other  substances  are  formed,  such  as 
xanthin,  uric  acid,  etc.  If  when  these  substances  are  formed,  they  are 
not  removed,  they  act  as  ashes  in  the  vital  furnace,  clog  the  fuel,  and 
lessen  oxidation.  Retained,  they  inevitably  interfere  with  the  nutrition 
and  function  of  cells,  and  disease  results.  If  taken  into  the  blood  and 
through  faulty  action  of  the  great  eliminant  organs — the  kidneys  and 
lungs — they  are  not  removed,  they  act  as  disturbing  elements  through- 
out the  body  ;  for  example,  should  the  functions  of  the  kidney  be  de- 
stroyed through  disease,  urea  is  not  eliminated,  and,  remaining  in  the 

3 


34  CAUSES  OF  DISEASE,   GENERAL  AND  LOCAL. 

circulating  fluids,  causes  symptoms  of  j)oisoning — uraemia.  Uric  acid 
is  normally  formed  in  small  amounts ;  if  formed  in  increased  amount 
and  not  eliminated,  owing  to  disease  of  the  kidneys,  it  gives  rise  to  a 
long  chain  of  symptoms,  characteristic  among  which  are  those  com- 
prised under  the  head  of  the  several  forms  of  gout.  It  is  extremely 
probable  that  many  diseases  of  obscure  nature  may  be  due  to  the  reten- 
tion and  circulation  of  waste-products. 

The  Presence  of  Poisons. — The  presence  of  introduced  poisons 
in  the  body,  such  as  mineral  and  vegetable  poisons,  must  be  regarded 
as  disease-causes  :  for  what  are  termed  the  symptoms  of  poisoning  by 
toxic  drugs  are  alterations  of  cell-nutrition,  and  hence  are  diseases ; 
short  and  violent  ones  in  many  instances,  prolonged  in  others  ;  for  exam- 
ple, the  chronic  poisoning  by  ergot  (see  works  on  materia  medica). 

Of  late  years  a  new  group  of  poisons  has  been  discovered,  which 
shows  that  toxication  is  widespread  and  common. 

Organic  poisons  are  formed  by  the  action  of  bacteria  (see  next  chap- 
ter) during  the  process  of  digestion,  are  absorbed,  and  give  rise  to  toxic 
symptoms.  Owing  to  the  presence  of  specific  bacteria,  poisons  are  gen- 
erated in  the  body,  which,  finding  their  way  into  the  circulatory  fluids, 
give  rise  to  symptoms  of  poisoning. 

The  Influence  of  Anaemia. — The  presence  of  oxidizable  material 
and  the  removal  of  the  oxidized  material  having  been  discussed,  there 
remains  another  important  factor — the  oxidizer  itself.  Oxygen  is 
received  by  the  red  blood-corpuscles  in  the  capillaries  of  the  lungs ;  it' 
combines  with  the  hemoglobin,  an  albuminate  of  iron,  forming  oxy- 
hemoglobin, which  in  the  capillaries  throughout  the  body  gives  up  its 
loosely  combined  oxygen  to  the  tissues,  is  reduced,  and  takes  up  carbon 
dioxid,  an  excretory  product.  It  is  evident,  therefore,  that  the  volume 
of  oxygen  distributed  throughout  the  body  depends  upon  the  amount 
of  hemoglobin  present — i.  e.,  upon  the  number  of  red  corpuscles  in  the 
blood.  A  deficiency  in  this  direction  means  lessened  oxidation  and  its 
attendant  effects. 

Condition  of  the  Circulatory  System. — If,  as  a  consequence  of 
faulty  action  on  the  part  of  the  heart  or  changes  in  the  structure  of 
the  bloodvessels,  the  blood  is  not  normally  distributed,  there  is  a  result- 
ant influence  upon  the  distribution  of  nutritive  material,  and  nutrition 
is  disordered ;  for  example,  if  as  a  consequence  of  disease  of  any  of 
the  heart-orifices  the  pressure  of  the  blood  in  the  vessels  is  lessened, 
changes  in  the  nutritive  balance  result.  If  as  a  result  of  changes  in 
the  walls  of  vessels  their  elasticity  is  lessened,  it  is  followed  by  faulty 
distribution  of  the  food-supply.  If  any  mechanical  interference  exist 
to  the  return-flow  of  the  blood,  stagnation  with  a  retention  of  waste- 
products  must  follow. 


EXCITING    CAUSES  OF  DISEASE.  35 

The  disease-causes  thus  far  discussed  have  relation  to  effects  upon 
the  chemistry  of  tissue-life  ;  there  remain  other  chisses  of  disease-causes 
of  great  frequency.  The  first  comprise  all  of  those  physical  conditions 
or  forces  which  act  upon  vital  tissues  and  depress  their  activity  or 
actually  destroy  them.  They  may  be  classed  under  the  head  of  abnor- 
mal physical  conditions/ 

Abnormal  Physical  Conditions. — This  class  of  disease-causes  in- 
cludes all  injuries  due  to  any  of  the  physical  forces.  All  surgical 
injuries  may  be  placed  under  this  head — diseases  due  to  trauma.  There 
are  also  included  in  the  group  diseases  arising  as  a  consequence  of 
obstruction  to  ducts  and  to  the  natural  outlets  of  the  body.  The  actual 
causes  of  disease  in  these  cases  are  secondary  effects  upon  nutrition, 
arising  out  of  faulty  nutrition,  and  very  frequently  in  consequence  of 
retained  waste-products. 

Among  the  intrinsic  causes  of  disease  should  be  mentioned  the  influ- 
ence of  the  nervous  system.  It  is  believed  by  some  physiologists  that 
there  are  special  nerve-fibres  whose  function  it  is  to  preside  over  the 
nutrition  of  the  parts  of  the  body  to  which  they  are  distributed ;  these 
have  been  called  trophic  nerves.  Unfortunately,  the  data  upon  which 
this  belief  is  founded  are  too  involved  and  too  few  to  base  positive 
opinions  upon.  It  has  been  noted  that  when  the  Gasserian  ganglion, 
the  ganglionic  centre  of  the  great  sensory  nerve  of  the  face,  has  been 
destroyed  ulceration  of  the  cornea  has  resulted,  which  has  been  attrib- 
uted to  the  destruction  of  trophic  nerves  ;  but  when  the  eyeball  is  pro- 
tected by  stitching  together  the  eyelids,  so  that  there  is  no  admission  of 
foreign  matters,  ulceration  does  not  occur.  The  more  rational  explana- 
tion, therefore,  is  that  the  ulceration  is  due  to  the  loss  of  sensibility, 
the  cornea  not  being  able  to  recognize  the  presence  of  the  foreign  body. 
Again,  injuries  to  nerves  are  followed  by  affections  of  parts  to  which 
the  nerves  are  distributed.  The  classical  example  of  this  is  that  of 
Charcot ;  the  occurrence  of  acute  bedsores  in  cases  of  certain  degen- 
erations of  some  portion  of  the  central  nervous  system,  which  cause 
paralysis.  Hyperemia,  inflammation,  and  necrosis  occur  in  rapid 
sequence  over  the  hip  or  over  the  sacral  region.  The  evidence  is,  how- 
ever, insufficient  to  prove  the  presence  of  special  trophic  fibres.  Many 
or  most  of  the  effects  are  perhaps  more  rationally  explained  by  the 
theory  of  vasomotor  influence  upon  nutrition.  The  calibre  of  the 
vessels  is  governed  by  special  fibres,  Avhich  by  causing  degrees  of  dila- 
tation of  the  walls  of  vessels  cause  modifications  of  nutrition  (see  chapter 
on  Vascular  Disturbances). 

Diseases  are  usually  classified  as  general  or  local :  the  first  class  are 
those  in  which  evidences  of  disturbance  exist  throughout  the  body  at 

^  Green's  Pathology  and  Morbid  Amitomy,  8th  ed. 


36  CAUSES  OF  DISEASE,   GENERAL  AND  LOCAL. 

large  ;  the  second,  those  in  which  the  disease-manifestations  are  confined 
to  some  sjDecial  region  of  the  body.  While  this  classification  is  useful 
in  describing  or  naming  distinguishing  features  between  diseases,  it  is 
faulty  in  that  it  fails  to  describe  the  actual  conditions  existing.  Some 
local  diseases  are  manifestations  of  a  general  disease-process  becoming 
evident  in  some  one  area ;  and,  again,  some  general  diseases  are  due 
primarily  to  disease  which  may  be  definitely  localized  in  one  region  of 
the  body.  For  example,  in  observing  a  typical  case  of  gout  it  might 
be  thought  that  the  disease  of  the  great  toe  was  a  local  malady,  when  it 
is  but  the  expression  of  a  general  cause  acting  locally ;  or,  again,  in 
observing  the  symptoms  of  typhoid  fever  it  might  be  believed  that  the 
disease  was  a  general  one,  which  in  one  sense  it  is,  but  the  primary 
cause  is  found  in  a  bacterial  ulceration  of  Peyer's  patches  in  the  small 
intestine,  the  constitutional  symptoms  being  caused  by  the  absorption 
and  circulation  of  the  poisons  generated  by  the  bacteria.  Year  by  year 
the  number  of  diseases  traceable  to  a  local  source  becomes  greater,  and 
the  number  classed  as  constitutional  grows  less. 


CHAPTER    III. 

BACTERIOLOGY,  WITH  SPECIAL  REFERENCE  TO  DENTAL 
PATHOLOGY  AND  THERAPEUTICS. 

Within  the  past  twenty  years  a  virtually  new  study  has  been  intro- 
duced into  medicine  and  surgery  and  their  dependents,  namely,  that  of 
Bacteriology.  It  is  not  to  be  understood  that  previous  to  this  time 
what  will  be  in  the  following  pages  studied  as  bacteria  were  unknown, 
but  that  it  is  only  within  that  period  that  such  modes  of  studying  these 
organisms  have  been  devised  as  render  the  study  of  direct  practical  use. 

In  1683^  Leeuwenhoek  described  bacterial  forms  obtained  from 
scrapings  of  the  human  teeth.  As  early  as  1762  Plenciz,^  of  Vienna, 
advanced  the  opinion  that  the  bacterial  forms,  or  animalcules  as  they 
were  called,  described  by  Leeuwenhoek  and  observed  by  himself, 
were  the  cause  of  all  infectious  diseases.  These  opinions  did  not  re- 
ceive general  endorseinent,  and  although  the  study  of  micro-organisms 
was  pursued,  it  was  not  until  some  eighty  years  after  that  the  germ- 
theory  of  disease  received  serious  attention,  when  Henle  taught  the 
modus  operandi  of  the  bacterial  origin  of  disease.^ 

The  invaluable  and  immortal  studies  of  Louis  Pasteur  demonstrated 
the  physiology  and  physiological  chemistry  of  bacteria,  and  showed  con- 
clusively the  nature  of  fermentative  processes. 

Koch,  through  the  devising  of  methods  of  isolating  varieties  of 
micro-organisms  based  upon  their  elaborately  worked-out  physiology, 
was  the  first  to  demonstrate  clearly  the  relations  between  bacteria  and 
infective  diseases.  Louis  Pasteur  had,  however,  previously  studied  and 
pointed  out  the  relationship  between  plant  and  animal  infectious  diseases 
and  bacteria,  and  had  shown  the  modes  of  effectually  combating  such 
diseases. 

Sir  Joseph  Lister's  name  has  been  so  closely  associated  with  that 
mode  of  surgical  operating  which  deals  with  the  freeing  of  wounds  from 
bacteria,  that  modern  antiseptic  surgery  is  known  as  Listerism. 

In  order  that  bacteria  as  disease-causes  may  be  studied  systematicallv, 
the  position  of  bacteria  in  the  life-scale  and  their  physiology  must  be 
examined  into.  It  is  noted,  first,  that  their  properties  show  them  to 
belong  to  the  vegetable  kingdom,  they  occupying  the  lowest  step  of  the 

'  Abbott's  Bacteriology.  2  jj,;^^  3  /^,-^/_ 

37 


38  BACTERIOLOGY. 

king:dom.  All  plants  ^  are  divided  into  two  great  classes,  Phanerogamia 
and  Cryptogamia.  Phanerogams  are  those  which  flower  and  reproduce 
by  seeds.  Cryptogams  are  destitute  of  flowers,  and  reproduce  through 
the  medium  of  spores.  Cryptogams  are  divided  into  two  groups,  those 
in  which  there  is  no  distinction  between  leaf  and  stem,  Thallophytes 
(Greek  thallos,  a  young  shoot,  and  jjUuton,  a  plant),  and  those  which 
bear  leaves,  as  many  water  plants. 

The  Thallophytes  are  subdivided  into  algse,  lichens,  and  fungi. 
The  last-named  order  is  that  with  which  bacteria  are  classed.  Fungi 
contain  no  chlorophyll,  and  hence  are  unable  to  derive  their  nutriment 
from  inorganic  material.  Chlorophyll,  the  green  coloring-matter  of 
plants  (chloi-os,  green,  and  phullon,  a  leaf),  is  the  substance  through  the 
agency  of  which  carbon  dioxid,  COg,  and  ammonia,  NH^,  are  broken 
up  and  built  anew  into  substances  fit  for  the  nutrition  of  plants.  It  is 
the  substance  which  effects  the  decomposition  of  water  and  carbon 
dioxid  and  their  recomposition  into  starch: 

6CO,  +  5HP  =  CgH^.O,  +  O,,. 

Fungi  are,  therefore,  compelled  to  derive  their  nutritive  material  from 
existing  organic  compounds,  which  is,  in  fact,  the  reason  why  they 
become  disease-causes.  They  are  subdivided  into  four  groups:^  1. 
Fission-fungi — Schizomycetes  ;  2.  Mould  or  thread-fungi — Hypho- 
mycetes ;  3.  Bud-fungi — Yeasts,  Blastomycetes ;  4.  Animal  fungi — 
Myeetozoa.  All  of  these  groups  are  interesting  as  throwing  light  upon 
many  of  the  problems  of  pathology,  and  it  is  quite  essential  to  compre- 
hend the  second  class  named  in  order  to  render  clear  the  physiology  of 
the  first  group,  which  is  one  of  immediate  and  special  interest  to  the 
pathologist. 

Bacteria  are  vegetable  organisms  of  extreme  minuteness,  many  of 
them  requiring  high-power  objectives  and  special  staining-methods  to 
make  them  visible.  OAving  to  their  methods  of  division  they  are 
termed  fission-fungi,  or  the  equivalent,  schizomycetes,  from  Greek  schizo, 
to  split  or  rend,  and  mukes,  a  fungus.  Like  many  other  cells,  they  possess 
a  cell-body  and  a  cell-wall,  and  some  of  them  a  nucleus  ;  their  substance 
and  cell-wall  are  composed  of  a  modified  protoplasm,  called  mycoprotein  ; 
the  cell-wall  of  some  is  composed  of  cellulose.  Some  of  them  possess 
flagella,  by  which  movement  is  effected.  They  are  devoid  of  chlorophyll, 
and  are  thus  unable  to  decompose  carbon  dioxid  and  water,  and  to  effect 
the  synthesis  of  starch  from  the  elements  of  those  compounds.  To 
secure  the  carbon  necessary  to  their  life-processes  they  require  to  be 
brought  in  contact  with  solutions  of  carbohydrates.     Their  nitrogen  is 

^  Thome,  Structural  and  Physiological  Botany. 
^  Miller,  Micro-organiums  of  the  Mouth. 


VARIETIES  OF  BACTERIA.  39 

derived  from  albuminous  substances  \vith  which  they  come  in  contact. 
Although  these  are  the  usual  sources  of  the  substances  required  for  the 
life  of  bacteria,  solutions  of  chemical  substances  may  be  made  in  which 
the  growth  of  the  organisms  proceeds.  The  conditions  necessary  to  their 
life  and  multiplication  are,  in  general,  the  same  as  for  all  living  bodies ; 
they  must  have  a  proper  food-sup})ly,  must  be  maintained  at  a  suitable 
temperature,  must  be  born  or  generated  with  normal  vitality,  and  must 
have  waste-products  removed  from  in  and  about  them.  These  factors 
vary  within  wide  limits,  as  will  be  seen  later.  Their  classification  is 
attended  with  much  difficulty ;  at  present  a  classification  based  upon  the 
form  of  the  organisms  appears  to  be  as  satisfactory  as  any.  They  are 
divided  into  three  great  groups — 

1.  The  micrococci  (tnikros,  and  koH-os,  a  berry),  including  all  of  the 
spherical  forms,  or  those  having  equal  or  nearly  equal  diameters. 


Fig.  6. 


°0    a. 


a  b 

c  d 

a,  staphylococci :  6,  streptococci :  c,  diplococci ;  (/,  tetrads  ;  f,  sarciuae.    (Abbott.) 

2.  The  bacilli  {baciUum,  a  rod),  or  rod-like  forms;   one   diameter 
being  greater  than  the  other. 

3.  The  spirillie  (Greek  sjjira,  a  coil),  or  the  curved  forms. 

All  of  these  groups  may  be  again  subdivided.  The  micrococci  are 
subdivided  according  to  their  modes  of  grouping.  Double  cocci  are 
called  diplococci  [diploos,  double).  If  in  division  the  cocci  arrange 
themselves  in  a  line,  they  are  called  streptococci  (streptos,  a  chain).  If 
they  agglomerate  in  bunches,  they  are  termed 
staphylococci  {staphyle,  a  grape).     The  organ-  ':,.''. 

isms,  upon  reproduction,  form  groups  which  are 
called  zooffloea  masses,  the  substance  holdino; 
them  together  being  formed  by  their  cell-walls. 
The  bacilli  are  of  many  and  varied  forms  and 
differ  as  to  their  modes  of  groupino-.     Thev      „  ..  ,        .,     ....    ,,.»,  ^^, 

i^         I      ^  '  Zooglcea  of  bacilh.    (Abbott.) 

exhibit,  in  the  same  species,  differences  of  form 

at  different  periods  of  their  development.     Many  of  them  form  spores 


40  BA  CTEBIOLOG  Y. 

(see  Fig.  8).     When    brought   under  conditions  unfavorable  to  their 
vitality   '^  individuals  themselves   undergo  alterations  in  their  outline 

Fig.  8. 

^^    ir  ><^^  \^^ 


d 


a,  bacillus  subtilis  with  spores ;  6,  bacillus  anthracis  with  spores ;  c,  Clostridium  with  spores ; 
d,  bacillus  of  tetanus  with  end-spores.    (Abbott.) 

with  the  appearance  of  so-called  involution-forms"  (Abbott).  The 
bacilli  may  again  assume  their  typical  forms  when  brought  under 
conditions  favorable  to  their  development. 


Fig.  9. 


^^1     I 


{ 


a  h 

a,  spirillum  of  Asiatic  cholera  (comma  bacillus) ;  b,  involution-forms  of  this  organism  as  seen  in 

old  cultures.    (Abbott.) 

Bacteria  may  be  again  divided,  according  to  their  mode  of  life,  into 
the  saprophytes  {sapros,  rotten,  and  phuion,  a  plant)  and  the  parasites 
(jKira,  near,  and  slteo,  I  nourish). 

The  saprophytic  fungi  are  those  which  derive  their  nutrition  from 
and  multiply  upon  dead  organic  matter  ;  they  are  the  forms  which  break 
down  dead  animal  matter  from  such  complex  molecules  as  albumin  into 
the  end-products — carbon  dioxid,  CO2,  ammonia,  NH3,  and  hydro- 
gen sulfid,  H2S.  Succeeding  varieties  of  this  group  form  from  albu- 
minous matters  a  series  of  substances  having  an  increasing  simplicity 
of  composition.  The  saprophytic  fungi  play  an  important  role  in  the 
economy  of  nature,  as  the  products  of  the  progressive  decomposition 
cited  serve  as  food  for  higher  plants. 

Parasitic  bacteria  are  those  which  develop  in  the  tissues  of  living 
animals  and  produce  disease  ;  they  form  the  greater  number  of  the 
group  known  as  pathogenic  organisms.  All  of  the  bacterial  forms 
are  to  be  found  in  this  class.  They  gain  access  to  the  body  through 
wounds,  frequently  large  surgical  wounds ;  by  surfaces  deprived  of  epi- 
thelium ;  a  minute  break  in  the  continuity  of  the  internal  or  external 
epithelial  covering  of  the  body  may  permit  the  entrance  of  the  organ- 
isms to  deeper  tissues,  where,  under  favorable  conditions,  they  multiply 
and  produce  their  specific  effects.      To  generalize  the  effects  of  the 


FERMENTATION.  41 

development  of  pathogenic  organisms  in  the  tissues  :  "  At  the  point  of 
multiplication,  degenerations,  necrosis,  inflammations,  and  new  growth 
of  tissues,  while  the  toxalbumins  produced  cause  manifestations  of 
poisoning.  According  to  the  variety  of  organisms,  one  or  more  of 
these  results  may  predominate  "  (Ziegler).  Many  forms  of  organisms 
have  points  of  election  in  which  they  find  the  most  suitable  soil  for 
development,  viz.,  the  typhoid  bacillus,  in  the  glands  of  the  ileum, 
Peyer's  patches  ;  the  diphtheria  bacillus,  in  the  mucous  surfaces  of 
the  pharynx  and  contiguous  parts. 

Many  bacterial  forms  find  a  suitable  habitat  in  the  human  mouth  ; 
the  conditions  of  their  food-supply  and  temperature  invite  the  habitation 
and  development  of  forms  of  all  three  of  the  groups  cocci,  bacilli,  and 
spirilla,  together  with  the  characteristic  leptothrix.  This  subject  will 
be  discussed  in  detail  later. 

In  order  to  comprehend  how  bacteria  act  as  pathogenic  or  disease- 
producing  agents  {pathos,  disease,  and  gennao,  I  produce)  an  examina- 
tion must  be  made  into  their  physiology  and  physiological  chemistry. 

Fermentation. 

Fermentation  may  be  defined  as  "  the  series  of  changes  which 
occur  in  solutions  of  organic  substances  exposed  to  the  air,  which  re- 
sult in  radical  changes  in  their  chemical  composition  ;"  as,  for  exam- 
ple, the  change  of  a  solution  of  sugar  into  alcohol  and  carbon  dioxid, 
and  later  into  acetic  acid,  the  formation  of  lactic  acid  in  milk,  the 
putrefaction  of  albuminous  substances,  and  so  on.  The  opinion  that 
these  changes  are  due  to  a  simple  oxidation  may  be  entirely  set  aside. 
Although  these  decompositions  are  due  to  oxidation,  hydration,  and 
reduction,  it  has  been  clearly  demonstrated  that  it  is  through  the  agency 
of  fungi,  and  not  mere  contact  with  the  oxygen  of  the  atmosphere. 

Sims  Woodhead  ^  comprehensively  defines  fermentation  "  as  essen- 
tially the  breaking  up  of  chemical  compounds,  the  molecules  of  which 
they  are  composed  being  separated  from  one  another  for  a  brief  period, 
and  then  allowed  to  combine  and  form  simpler  and  more  stable  com- 
pounds ;  owing  to  the  setting  free  of  such  energy  as  has  been  stored  up 
in  the  highly  complex  fermentable  substance  which  is  no  longer  required 
to  maintain  the  high  level  of  combination,  a  certain  proportion  of  this 
energy  is  released  in  the  form  of  heat ;  the  temperature  of  a  fermenting 
fluid  is  found  to  rise  without  the  addition  of  any  external  heat." 

If  to  a  watery  solution  of  sugar,  or  an  infusion  of  vegetable  juices 

containing  sugar,  a  yeast  (a  bud-fungus,  one  of  the  blastomycetes)  be 

added,  and  the  fluid  be  maintained  at  a  temperature  of  35°  C,  it  will 

be  found  that  there  is  an  evolution  of  gas,  which,  if  passed  into  lime- 

^  Bacteria  and  Their  Products,  p.  87. 


42  BACTERIOLOGY. 

water,  gives  a  precipitate — i.  e.,  the  carbon  dioxid  has  combined  with 
the  calcium  of  the  lime-water  to  form  calcium  carbonate ;  the  temperature 
of  the  solution  rises  above  that  of  the  surrounding  atmosphere,  and  a 
test  Avill  show  alcohol  to  be  present  in  the  solution  and  the  sugar  to  have 
largely  disappeared.  Boiling  the  solution  before  adding  the  yeast  does 
not  prevent  fermentation.  Boiling  the  solution  immediately  after  add- 
ing the  yeast  prevents  fermentation — i.  e.,  boiling  the  fungus  prevents 
its  action,  its  vitality  is  destroyed.  If  a  quantity  of  carbolic  or  sali- 
cvlic  acid,  or  mercuric  chlorid,  be  added  to  the  solution,  fermentation 
does  not  occur.  If  the  temperature  of  the  solution  be  loM^ered,  the 
process  is  much  less  active.  If  the  access  of  free  oxygen  be  prevented, 
fermentation  does  not  occur,  which  illustrates  that  in  fungi,  as  in  all  liv- 
ing cells,  the  vitality  is  lessened  or  destroyed  by  an  insufficient  food- 
supply  and  an  unsuitable  temperature  ;  and,  finally,  it  will  be  noticed  that 
after  a  period  fermentation  ceases.  If  after  a  period  some  of  the  yeast 
be  removed  from  the  solution,  it  will  be  found  that  it  has  lost  the  power 
of  inducing  fermentative  changes  in  other  solutions  in  which  it  may  be 
placed — it  is  dead  :  dead  because  of  an  accumulation  of  its  waste-prod- 
uct, alcohol,  about  it.  As  with  all  vital  cells,  if  their  waste-products  are 
not  removed,  the  cells  are  smothered  in  their  own  excreta.  This  is  the 
example  of  fermentation  usually  cited,  but  very  many  other  types  exist. 

If  to  a  solution  of  sugar  a  minute  portion  of  the  scrapings  taken 
from  a  carious  tooth-cavity  be  added,  and  the  solution  maintained  at  a 
temperature  of  about  35°  C,  it  wall  be  found,  after  a  time,  that  the 
solution  has  acquired  an  acid  reaction,  and  a  chemical  test  will  show 
that  lactic  acid  has  formed.  A  microscopic  examination  of  the  solu- 
tion will  demonstrate  the  presence  of  a  large  number  of  the  fission- 
fungi  forms.  As  each  of  these  forms  has  probably  its  own  peculiar 
physiology,  several  fermentations  have  been  in  progress,  although  lactic 
fermentation  predominates.  Miller  ^  has  shown  that  this  fermentation 
ceases  when  the  amount  of  acid  present  exceeds  0.75  per  cent.,  this  being 
the  excess  of  waste-products  which  inhibits  the  vitality  of  the  fungi. 

These  general  principles  govern  the  vital  processes  of  all  of  the 
fungi,  including  the  schizomycetes  group,  although  the  several  varieties 
of  bacteria  have  peculiar  conditions  of  life  which  are  qualifying  clauses 
to  the  general  proposition. 

While  it  is  shown  that  for  the  development  of  the  yeast  fungus  and 
also  for  many  of  the  bacterial  forms  the  presence  of  free  oxygen  is 
essential,  there  are  others  which  develop  in  the  absence  of  free  oxygen, 
and  still  others  which  develop  either  with  or  without  the  presence  of 
free  oxygen.  Bacteria  have,  therefore,  been  classified  by  Pasteur  into 
the  aerobic,  or  those  requiring  free  oxygen ;  anaerobic,  those  which 
^  Micro-organisms  of  the  Mouth. 


FERMENTATION.  43 

develop  in  its  absence  ;  and  facultative-anaerobic,  those  which  develop 
with  or  without  the  presence  of  free  oxygen — or,  1st,  obligatory  aerobics  ; 
2d,  obligatory  anaerobics  ;  3d,  facultative-anaerobics. 

A  single  species  of  bacteria  rarely  or  never  exists  alone  in  a  solu- 
tion of  organic  matter,  except  as  a  result  of  special  precaution  upon 
the  part  of  the  investigator.  Mixed  cultures  are  the  rule.  When  a 
number  of  species  are  introduced  or  are  present  some  develop,  others 
are  quiescent ;  some  find  conditions  favorable  to  their  growth,  others  do 
not ;  but  if  the  conditions  be  altered,  a  second  or  third  variety  prevails. 
Organisms  may  find  in  a  field  rendered,  by  an  excess  of  waste-products, 
an  improper  culture-medium  for  one  form  of  bacteria,  a  suitable 
medium  in  which  to  grow,  so  that  progressive  decomposition  occurs 
in  the  medium.  For  example,  in  the  successive  stages  of  the 
breaking  down  of  albuminous  substances  the  compounds  formed, 
while  rendering  the  soil  unfit  for  the  life  of  the  first  invading  organ- 
isms, fit  it  for  the  growth  of  other  varieties,  which  effect  further 
decompositions. 

By  processes  of  oxidation,  reduction,  and  hydration  many  forms 
of  bacteria  effect  a  gradual  decomposition  of  albuminous  matter. 
Peptones,*  substances  having  a  less  complex  composition,  are  first 
formed ;  next,  bodies  of  the  compound  ammonia  type  appear,  the 
chemical  and  physiological  equivalents  of  alkaloids  derived  from  the 
higher  plants,  and  hence  called  ptoma'ins  or  animal  alkaloids.  Suc- 
ceeding this,  such  nitrogenous  bases  as  leucin,  ty rosin,  and  the  amins 
(methyl-,  ethyl-,  and  propyl-amin)  are  formed.  Next,  fatty  acids  and 
such  acids  as  butyric,  lactic,  and  succinic,  appear ;  next  aromatic  prod- 
ucts, such  as  indol,  phenol,  and  cresol,  are  formed ;  and  the  final 
decomposition  is  represented  in  the  end-products — carbon  dioxid,  CO,, 
hydrogen  sulfid,  HgS,  ammonia,  NH,,  and  water,  H^,0. 

Several  forms  of  bacteria  when  grown  in  solutions  of  albumin  pro- 
duce substances  of  complex  composition  which  act  as  poisons  when 
introduced  into  the  bodies  of  animals ;  these  are  termed  toxalbumins. 
Many  forms  of  bacteria  when  introduced  in  minute  quantities  into  solid 
or  gelatinous  albuminous  matter  and  kept  at  a  proper  temperature  are 
found  to  increase  in  number ;  the  gelatinous  material  around  them 
becomes  liquefied  and  undergoes  decomposition,  with  the  formation  of 
substances  which,  introduced  into  living  animals,  act  as  poisons.  If 
the  solutions  thus  obtained  be  boiled  and  filtered,  so  that  they  are 
entirely  free  from  the  presence  of  the  organisms  which  produced  them, 
and  then  injected  under  the  skin  of  an  animal,  evidences  of  widespread 
disorder  are  exhibited — the  animal  is  poisoned.  The  effects  will  be 
governed,  first,  by  the  nature  of  the  organisms  producing  the  poison, 

'  Ziegleij   General  Patholocjy,  1895. 


44  BACTERIOLOGY. 

some  producing  more  virulent  substances  than  others  ;  and,  secondly, 
upon  the  size  of  the  dose  employed.  If  the  eifects  pass  away,  the  health 
of  the  animal  is  restored.  If,  on  the  contrary,  the  organisms  them- 
selves be  introduced  into  the  body,  symptoms  of  poisoning  appear  and 
increase  in  severity,  even  though  but  few  organisms  be  introduced.  In 
some  cases  the  symptoms  persist  until  the  death  of  the  animal ;  in 
others  they  gradually  disappear.  If  a  portion  of  the  tissue  in  which 
the  organisms  were  introduced  is  used  to  inoculate  other  animals, 
similar  symptoms  appear  in  them.  It  is  evident,  therefore,  that  bac- 
teria generate  in  the  tissues  substances  which  act  as  poisons. 

Some  species  or  forms  exhibit  a  predilection  for  special  tissues 
of  the  body ;  for  example,  a  special  bacillus  develops  in  the  glands 
of  the  ileum ;  others  have  a  predilection  for  the  large  intestine,  some 
for  the  spleen,  others  for  portions  of  the  nervous  system,  and  so  on  ;  and 
possibly  owing  to  the  peculiar  physiological  chemistry  of  the  part  af- 
fected and  to  the  species  of  bacteria,  specific  poisons  are  generated, 
which,  taken  into  the  circulation,  produce  characteristic  symptoms. 

Ferments. — The  cells  of  the  living  body  produce  substances  which 
have  the  power  of  transforming  or  changing  the  chemical  composition  of 
organic  matter ;  for  example,  the  epithelial  cells  of  the  salivary  glands 
produce  a  substance  which  converts  starch,  nCeH-^oO^,  into  glucose, 
CgIIi206,  a  process  of  hydration.  The  cells  of  the  peptic  glands  of  the 
stomach  produce  a  substance  which  changes  albumin  into  peptone,  prob- 
ably also  a  hydration.  The  cells  of  the  pancreas  produce  substances 
which  cause  the  hydration  of  starch  and  of  albumin  and  the  formation  of 
leucin  and  tyrosin.  Such  substances  are  known  as  ferments.  They  ap- 
pear to  take  no  part  in  the  decompositions  which  they  effect,  and  are 
called  unformed  ferments.  The  small  plant-cells — bacteria — also  give 
rise  to  bodies  which  effect  similar  changes,  or  the  changes  may  occur  in 
the  cells  themselves.  It  is  through  the  agency  of  these  latter  substances, 
called  "  organized  ferments,"  that  the  decompositions  are  effected  which 
result  in  the  chain  of  substances  described  under  the  decomposition  of 
albumin.  It  is  by  reason  of  this  property  that  bacteria  act  as  disease- 
causes,  and  are  capable  of  disturbing  the  physiology  of  the  body. 
"  When  pathogenic  fungi  succeed  in  growing  in  the  living  body,  if 
infection  takes  place,  their  action  is  in  general  characterized  at  the  point 
of  multiplication  by  degeneration,  necrosis,  inflammation,  and  a  new 
growth  of  tissue,  while  the  toxalbumins  produced  by  them  cause  mani- 
festations of  poisoning."  ^ 

Many  of  the  forms  of  bacteria,  both  saprophytic  and  parasitic, 
are  found  in  ordinary  drinking-water.  Many  of  them,  particularly 
the  spores  of  bacilli,  are  found  floating  in  the  air ;  the  soil  to  the 
'  Ziegler,   General  Pathology,  1895,  p.  440. 


FERMENTS.  45 

depth  of  a  metre  (forty  inches)  contains  numerous  varieties.  Above 
certain  altitudes  they  are  rarely  found,  and  they  are  rare  in  the  atmos- 
phere of  mid-ocean.  At  ordinary  levels  in  temperate  and  tropical 
climates  they  are  nbiquitous.  They  cling  to  most  of  the  snrfaces  of 
bodies  ;  are  found  on  the  skin  and  in  its  folds  ;  insinuate  themselves  into 
the  mouths  of  sweat  and  sebaceous  glands,  and  swarm  in  the  intestines 
and  frequently  in  the  mouths  of  animals.  Among  all  of  the  varieties 
thus  distril)uted,  there  are  some  which,  gaining  entrance  to  the  tissues  of 
the  body,  produce  destructive  diseases — /.  e.,  they  are  pathogenic.  Or- 
ganisms capable  of  inducing  disease-conditions  in  the  body  are  found  in 
all  three  of  the  form-groups — cocci,  bacilli,  and  spirilla.  Many  varieties 
of  each  of  these  classes  have  been  shown  to  possess  constant  patho- 
genic features,  and,  further,  they  have  been  proved  so  constant  attend- 
ants upon  defined  diseases  that  a  causative  relationship  has  been  made 
out  between  the  organisms  and  the  disease.  Special  cultures  of  one 
variety  introduced  into  the  body  produce  always  the  same  symptoms, 
and  secondary  cultures  taken  from  the  diseased  organ  induce  the  identi- 
cal disease  in  other  individuals. 

A  varietv  of  coccus  which  when  cultivated  forms  oranw-colored  col- 
onies,  and  liquefies  the  gelatin  upon  which  it  is  grown,  when  intro- 
duced into  the  body  is  followed  by  pus-formation — /.  e.,  it  is  pyogenic 
(from  puon,  pus,  and  ^enn«o,  I  produce).  From  the  manner  in  which 
the  organisms  collect  into  groups  they  are  called  staphylococci  (from 
staphyle,  a  bunch  of  grapes)  ;  they  are  thus  designated  as  the  staphylo- 
coccus pyogenes  aureus,  the  aureus  from  the  orange  color.  Another 
pyogenic  variety  gives  white  colonies  ;  hence  it  is  called  the  staplivlo- 
coccus  pyogenes  albus.  Another,  producing  blue  cultures,  is  called  the 
staphylococcus  pyogenes  cyaneus.  Still  another,  forming  green  colonies, 
is  called  the  staphylococcus  pyogenes  viridis. 

Several  forms  of  bacilli  have  been  shown  to  induce  pus-formation  ; 
hence  are  called  pyogenic  bacilli. 

A  specific  bacillus  has  been  shown  to  produce  Asiatic  cholera,  and 
from  its  form  is  called  the  comma  bacillus.  Another  induces  breakiuir 
down  of  tissue  by  the  formation  of  tubercles,  hence  named  the  tubercle 
bacillus — the  bacillus  tuberculosis,  the  exciting  cause  of  pulmonary 
phthisis  and  of  diseases  of  the  skin,  joints,  etc.  To  another  variety  of 
bacillus,  typhoid  fever  is  directly  traceable.  Numerous  forms  of  cocci 
and  bacilli  when  introduced  into  the  tissues  are  followed  by  evidence 
of  blood-poisoning,  or  septicaemia  (Greek  septikos,  that  which  produces 
putrefaction,  and  haima,  the  blood).  They  are  the  bacilli  or  cocci  of 
septicemia.  Several  varieties  found  in  the  mouth  are  capable  of  causing 
these  symptoms,  and  hence  are  known  as  the  bacilli  sputum  sp]>tic8emia. 

It  is  interestino;  and  necessary  to  note  that  in  manv  instances  when 


46 


BACTERIOLOGY. 


organisms  are  introduced  into  the  body  their  action  is  self-limited,  and 
in  some  cases  a  body  once  infected  and  recovered  is  insusceptible  to 
future  introductions  of  the  same  organism  (see  Immunity,  Chapter  II.). 

Bacteria  of  the  Mouth. 

To  the  dental  practitioner  the  forms  of  bacteria  which  are  constant 
and  those  which  are  occasional  inhabitants  of  the  human  mouth  are  of 
prime  interest.  Many  of  the  saprophytic  fungi  are  constantly  present, 
finding  in  the  food-debris,  dead  epithelium,  abundant  moisture,  and 
suitable  temperature,  an  extremely  favorable  soil  in  which  to  flourish. 

The  other  two  subdivisions  of  fungi,  in  addition  to  the  schizomycetes, 
occasionally  develop,  as,  for  example,  the  bud-fungus  (saccharomyces, 
oidium  albicans),  which  produces  in  neglected  children  the  form  of 
stomatitis  called  thrush. 

Up  to  1885  Miller^  had  isolated  twenty-two  different  forms  of 
bacteria  from  the  human  mouth.  Ten  of  the  twenty-two  were  cocci ;  as 
in  Figs.  10-13 ;  some  small,  some  very  large.  Five  were  short  rods 
(Figs.  14,  15).     A  curved  species,  which  liquefied  gelatin  and  produced 


Fig.  10. 


a 


Fig.  11. 


Fig.  12. 


Fig.  13. 


Fig.  14. 


Fig.  15. 


F0g 

0O  \ 


Fig.  18. 


Fig.  16. 


Bacteria  of  the  mouth.    (Miller.) 

a  green  coloring-matter,  was  called  vibrio  viridans  (Fig.  18).  Spirilla 
and  the  leptothrix  were  found.  Of  thirty  species  cultivated  later, 
eighteen  were  cocci,  eleven  rods,  and  but  one  thread  form. 

"  Of  the  twenty-two  forms  first  described  sixteen  brought  about  an 
acid  reaction  when  cultivated  in  beef-extract  peptone  sugar  solutions. 
Several  of  the  forms  possess  the  power  of  converting  sugar  into  lactic 
acid.    In  some  cases  the  lactic  fermentation  is  attended  by  the  evolution 

^  Micro-organisms  of  the  Mouth. 


BACTERIA    OF  THE  MOUTH.  47 

of  gases,  COj  and  H,  and  if*  albumin  be  present  HgS  may  be  generated  ; 
in  others  there  is  no  formation  of  gases.     There  are  a  number  of  bac- 
teria wliich  almost  invariably  occur  in  every  mouth." 
Mouth  bacteria  proper : 

1.  Leptothrix  innominata  ; 

2.  Bacillus  buccalis  maximus  ; 

3.  Leptothrix  buccalis  maxima  ; 

4.  Jodococcus  vaginatus  ; 

5.  Spirillum  sputigenum  ; 

6.  Spirochfete  dentium  (denticola). 

These  are  all  uncultivable,  so  that  their  physiology  is  not  made 
out.  Vignal  found  ^  among  seventeen  varieties  of  mouth  bacteria  the 
bacterium  termo,  bacillus  subtilis,  staphylococcus  pyogenes  aureus  and 
albus. 

In  addition  to  the  forms  named,  the  following  varieties  of  pathogenic 
fungi  have  been  isolated  from  the  mouth  :  ^ 

Micrococcus  of  sputum  septicaemia  ; 

Micrococcus  tetragenus  ; 

Bacillus  salivarius  septicus  ; 

Streptococcus  septopypemicus  ; 

Micrococcus  gingivae  pyogenes ; 

Bacterium  gingivae  pyogenes ; 

Bacillus  dentalis  viridans  ; 

Bacillus  pulpse  pyogenes  ; 

Pyogenic  micrococci ; 

Actinomyces  ; 

Saccharomyces  albicans  ; 

Spirillum  sputigenum  ; 

Pane's  pneumococcus ; 

Bacillus  saprogenes  ; 

Streptococcus  salivarius  pyogenes ; 

Coccus  salivarius  septicus  ; 

Micrococcus  biskra  ; 

Bacillus  bronchitidis  putridse  ; 

Bacillus  tussis  convulsivae ; 

Bacillus  pneumoniae  ; 

Bacillus  pneumosepticus  ; 

Pneumobacillus. 
Of  111    mice  in  whose  abdominal  cavities  human  saliva  was  intro- 
duced, but  10  survived,  the  others  dying  in  from  fifteen  hours  to  forty 
days,  42  of  them  within  forty -eight  hours."*     In  most  of  these  cases  the 

^  Archives  de  Physiologic,  norm,  et  pathoL,  1886,  No.  8. 

=*  Miller.  Dental  Co.s?nos,  Nov.,  1891.  *  Ibid. 


48  BACTERIOLOGY. 

micrococci  of  sputum  septicaemia  were  found  in  a  sero-purulent  exuda- 
tion in  the  peritoneal  cavity.  In  16  cases  micrococcus  tetragenus  was 
present.  In  over  30  cases  cocci,  staphylococci,  streptococci,  and  diplo- 
cocci  were  present. 

Miller  divides  the  organisms  into  two  classes,  according  to  the 
mode  of  death  of  the  animals  attacked  :  first,  those  which  produce 
speedy  death  through  blood-poisoning  with  but  comparatively  slight 
local  reaction ;  secondly,  those  which  induce  fatal  pyogenic  processes 
at  the  point  of  injection. 

To  recapitulate  :  the  human  mouth  swarms  with  bacteria  of  the 
several  classes ;  lactic,  acetic,  and  butyric  acid  ferments ;  numerous 
saprophytic  fungi ;  and  organisms  producing  specific  disease-conditions 
when  introduced  into  the  tissues.  The  pyogenic  organisms  are  almost 
constantly  present. 

Phagocytosis. 

The  tissues  of  the  body  do  not  play  an  entirely  passive  part  in 
the  diseases  caused  by  bacteria.  While  many  tissue-cells  of  the  body 
exhibit  a  resistance  to  and  in  some  cases  wage  a  Avarfare  against  invad- 
ing organisms,  the  resistance  is  much  more  marked  in  some  instances 
than  in  others.  It  had  been  observed,  I860-' 70,  by  von  Reckling- 
hausen, Rindfleisch,  Ponfincks,  and  others,  that  certain  cells  of  the 
body  took  into  themselves  particles  of  dust  and  the  material  of  dis- 
integrated blood-corpuscles.  In  1874  Ziegler  observed  the  fibroblasts 
of  granulation-tissue  take  up  and  destroy  leucocytes — devour  them. 
The  wandering  cells  of  the  body,  loaded  with  dust-particles  and  other 
foreign  matter,  appear  upon  the  surface  of  mucous  membrane. 

In  1884  Metchnikoif'  published  the  results  of  a  series  of  studies 
made  by  him,  principally  upon  the  Daphnia,  small  fresh-water  Crus- 
tacea.    He  observed  that  when  the  spores  of  the  monospora  cuspidata, 

Fig.  20. 


1,  a  spore  which  has  penetrated  the  intestinal  wall  and  entered  the  abdominal  cavity,  where  four 
leucocj'tes  have  surrounded  its  end :  m,  the  muscular  layer  of  the  intestine ;  e,  epithelial  layer ; 
.?,  the  serous  layer.  2,  a  spore  surrounded  by  leucocytes  from  the  abdominal  cavity  of  a  Daphne. 
(Metehnikoff.) 

a  bud-fungus,  gained  access  to  the  alimentary  canal  of  the  animal  it 

'  Fortschritte  der  Med.,  Bd.  ii.      See    Comparative  Pathology  of  Inflammation  (same 
author). 


PHAGOCYTOSIS. 


49 


Fig 


passed  into  the  abdominal  cavity  througli  tlio  intestinal  walls.  As  soon 
as  it  entered  the  cavity  it  was  attacked  by  leucocytes  (Fig.  20),  which 
took  the  spores  into  their  bodies,  and  devoured  and  digested  them.'  "  If 
the  Daphnia  is  healthy,  the  monospora  is  gradually  overcome  ;  but  if 
the  animal  be  feeble  or  the  monospora  is  ingested  in  very  large  quan- 
tities .   .  .  the  animal  may  eventually  succumb  to  the  attack." 

The  wandering  cells  of  the  body  have  also  been  shown  to  possess  this 
power,  which  MetchnikofF  has  termed  Phagocytosis — phago,  I  eat,  and 
ciftos,  a  bud  (see  Inflammation). 

The  reasons  set  forth  l)y  Metchnikoff,  that  this  is  Nature's  means 
by  which  the  living  tissues  defend  themselves  against  invaders,  and  that 
these  cells  are  specifically  designed  for  this  purpose,  require  modifica- 
tion. It  is  probably  an  expression  of  the  nutritive  function  of  simple 
cells.  The  process  is  not  universal  throughout  the  body,  for  in  some 
instances  the  bacteria  are  taken  up  by  the  leucocytes,  and  in  others  they 
are  left  undisturbed. 

Researches  of  Leber,  Buchner,  and  others  have  shown  that  leucocytes 
may  be  repelled  by  certain  chemical 
substances  and  attracted  by  others. 
This  property  of  attraction  and  re- 
pulsion has  been  termed  chemotaxis  ; 
positive  when  attraction  exists,  neg- 
ative when  there  is  repulsictn.  Buch- 
ner found  that  substances  derived  from 
certain  bacteria,  even  in  high  dilution, 
possessed  positive  chemotactic  prop- 
erties, and  that  certain  organic  deriv- 
atives, such  as  methylamin,  leucin, 
tyrosin,  and  urea,  exhibit  negative 
chemotaxis." 

It  is  beyond  question  that  ])hago- 
cytosis  plays  an  important  part  in  the 
prevention  of  disease  and  the  removal 
of  foreign  substances  which  gain  ac- 
cess to  the  tissues,  or  are  formed  in 
the  body.  It  is  not  the  leucocytes 
alone  which  possess  this  power  (Fig. 
21).  The  endothelial  cells  of  blood- 
vessels have  this  function,  as  have 
several  other  forms  of  mesodermal  cells  (Metchnikoff),  notably  the 
wandering  corpuscles  of  connective  tissue. 

^  Woodhead,  Bacteria  and  Their  Products,  1891  ;  and  Metchnikoff,  Il)id. 
'^  This  subject  is  discussed  at  length  in  Ziegler's  General  Pathology,  1895. 


Active  phagocytosis.  Endothelial  cells  en- 
closing the  bacilli  of  swine  septicaemia, 
from  an  hepatic  vein  of  a  pigeon  :  a,  endo- 
thelial cells ;  b,  leucocytes.   (Metchnikoff.) 


50  BACTERIOLOGY. 

Hugenschmidt  ^  has  shown  that  the  filtered  saliva  of  the  human 
mouth,  containing  necessarily  quantities  of  bacterial  products,  possesses 
marked  positive  chemotactic  properties. 

Nuttall  ^  showed  that  the  filtered  serum  of  the  blood  possessed  bac- 
tericidal power,  and  that  degeneration  of  ingested  bacteria  occurred  be- 
fore the  process  of  phagocytosis.  Buchner  found  that  the  activity  of  the 
serum  against  l)acteria  was  greater  when  deprived  of  its  cellular  elements. 
Boiling  for  half  an  hour  destroyed  the  property.  By  dialysis  or  ex- 
treme dilution  with  distilled  water  its  germicidal  energy  was  checked  ; 
but  if  an  equal  dilution  was  made  with  sodium-chlorid  solution  (0.6-0.7 
per  cent.),  the  bactericidal  power  was  not  lost,  Hankin,^  Ogatta,  and 
others  have  isolated  from  the  spleen,  lymphatic  glands,  and  blood,  glob- 
ulins which  in  solution  have  germicidal  power.  Buchner  has  suggested 
that  these  germicidal  substances  be  called  "  alexins."  Noting  the  con- 
ditions under  which  serum  germicides  are  observed,  Vaughan  *  and  also 
Halliburton^  conclude  that  the  substance  to  which  the  germicidal 
power  is  due  is  a  nuclein. 

^  Dental  Cosmos,  vol.  38,  p.  797  et  seq. 

^  See  Abbott's  Princrples  of  Bacteriology,  p.  425.  ^  Ibid. 

*  Ptomains  and  Leucoma'ins.  ^  Chemical  Phys.  and.  Path. 


CHAPTER   IV. 


DISTURBANCES  OF  NUTRITION :  ATROPHY,  DEGENERATION, 
NECROSIS,  HYPERTROPHY,  TUMORS. 

Owing  to  various  disease-causes  to  which  the  tissues  of  the  body- 
may  be  subjected,  they  may  suffer  an  alteration  in  the  normal  con- 
tinuity of  the  cycle  represented  by  development,  growth,  maintenance, 
and  that  gradual  lessening  of  vitality  which  precedes  the  death  of  an 
individual.  If  there  be  such  interference  with  the  process  of  develop- 
ment that  an  organ  is  much  below  normal  in  size,  the  condition  is 
spoken  of  as  aplasia  or  agenesia.  If  the  interference  merely  checks  the 
growth  of  a  developed  organ,  the  condition  is  known  as  hypoplasia.^ 
It  is  with  disturbances  arising  during  the  period  of  maintenance  that 
this  chapter  is  concerned. 

Disorders  of  nutrition  are  of  two  classes  :  in  one  class  there  is  an 
excess  of  nutrition ;  in  the  other  there  is  a  deficiency.  In  either 
class  disturbance  in  the  nutritive  equilibrium  alters  the  vitality  of 
tissue-cells.    In  one  case,  if  stimulation  be  the  process  in  operation,  it  is 

Fic4.  22. 
Health 


IJ  . 

Stimulation       / 

>.           (Sedation) 
\           Atony 

o 

Irritation         / 

\ 

1 

(Hyperaemia) 
Inflamviation 

' 

1 

'"^,  .Degeneration 
Atrophy 

(Degeneration) 
Overwork-Paralysis 

Paralysis  Starvation 

Death  (Necrosis) 

but  a  question  of  time  and  degree  until  the  death  of  the  cells  is  brought 
about.  In  the  other  case,  if  sedation  be  the  influence  at  Avork,  it  is  also 
but  a  question  of  time  and  degree  until  the  cells  succumb.  The  extent 
of  the  degree  of  interference  with  nutrition,  whether  hyper-  or  hypo- 
nutrition,  depends  upon  the  extent  of  the  influence  in  operation,  the 
^  Ziegler,  General  Pathology,  1895. 

51 


52  DISTURBANCES  OF  NUTRITION. 

effects  ranging  from  slight  disturbance  of  function  to  death  of  a  part. 
The  nature  of  these  effects  is  graphically  represented  in  Fig.  22.  The 
two  horizontal  lines  farthest  separated  represent  health  and  death. 
Descending  from  the  health-line  to  the  death-line  are  the  curved  lines 
of  a  semi-ellipse,  the  path  from  health  to  death  being  a  gradual,  not  a 
precipitate  fall  to  death,  in  conditions  of  altered  nutrition.  It  will  be 
observed  that  these  curved  lines  are  crossed  at  intervals  by  straight 
horizontal  lines,  which  represent  stages  in  the  vital  descent,  or  grades 
of  nutritive  disturbance.  If  a  general  survey  be  taken  of  these  several 
stages,  based  upon  the  observed  phenomena  of  cell-life,  deductions  as 
to  the  nature  of  the  alterations  of  physiology  occurring  may  be  made  as 
illustrative  examples. 

Hypbrnutrition. 

The  effect  of  stimulation,  first,  upon  the  functions  of  organs,  and, 
pari  passu,  upon  their  vascular  supply  (see  Chapter  V.),  is  represented 
by  an  increased  nutrition.  The  irritability,  contractility,  and  general 
functional  activity  of  the  part  are  increased.  More  food  is  appro- 
priated, oxidation  is  increased,  and  hence  more  energy  is  set  free  and 
more  work  is  done.  Stimulation  is  therefore  followed  by  an  increase 
of  functional  activity.  If  the  functions  of  the  part  be  secretory,  secre- 
tion is  increased.  Connective-tissue  cells,  whose  function  is  the  forma- 
tion of  basis-substances,  form  them  in  increased  amount.  Increase  the 
stimulation,  and  the  effect  is  one  of  irritation  :  vital  processes  become 
fretful,  incomplete  chemical  changes  occur  in  the  cells,  and  functional 
activity  is  disordered.  The  energy  developed  in  the  cells  of  tissues 
manifests  itself  in  nutritive,  functional,  or  reproductive  activities  (Vir- 
chow),  and  hence,  as  the  energy  is  developed  in  definite  amount,  if  it  be 
expended  in  one  of  these  three  directions,  the  other  two  must  be  corre- 
spondingly diminished.  Thus  irritation  may  be  followed  by  increased 
secretion  or  functional  activity,  an  altered  metabolism  in  the  cells ;  or 
the  cells  may  exercise  their  reproductive  function,  in  which  case  the 
number  of  cells  is  increased — i.  e.,  a  part  becomes  hypertrophied. 

HYPERTROPHY  OR  HYPERPLASIA. 

By  hypertrophy  is  meant  an  increase  in  the  size  of  some  organ,  or 
portion  of  it,  or  of  any  tissues.  Hypertrophy  may  be  either  simple  or 
numerical.  Sim])le,  when  the  increase  of  volume  is  due  to  an  increase 
in  the  size  of  cells  ;  numerical,  when  due  to  an  increase  in  the  number 
of  cells. 

Causes. — Hypertrophy  occurs  when  nutrition  in  a  part  exceeds  the 
waste.      In  general  terms,  it  is  caused   by  a  continued  irritation  of 


HYPERTROPHY  OR  HYPERPLASIA.  53 

definite  grade.  It  is,  as  a  rule,  intimately  associated  with  a  parallel 
increase  in  the  local  circulation  of  a  part  (see  Chapter  V.  and  Fig.  22;. 

Hyperplasia  is  frequently  a  reflex  nutritive  change  due  to  an  increased 
demand  for  work  being  made  upon  tissues ;  for  example,  when  a  muscle 
is  repeatedly  urged  to  an  unusual  amount  of  work  short  of  marked 
fatigue,  an  increase  in  its  function  occurs,  its  capacity  for  work  becomes 
greater,  and  if  the  strong  stimulus  (mild  irritation)  implied  be  con- 
tinued, the  cells  increase  in  size,  and,  it  may  be,  in  number  :  all  three 
phases  of  the  expenditure  of  an  increase  of  vital  energy  being  repre- 
sented— functional,  nutritive,  and  reproductive.  This  is  also  repre- 
sented in  the  reaction  of  the  alternately  acting  and  resting  heart-mus- 
cles. If  an  unusual  and  continuous  strain  be  placed  upon  the  heart 
owing  to  an  increase  in  the  resistance  it  is  normally  called  upon  to 
overcome,  an  increase  of  the  volume  of  the  muscles  follows. 

Tissues  or  organs  accustomed  to  performing  work,  if  deprived  of 
the  work,  use  the  developed  vital  energy  in  reproduction,  and  hyper- 
trophy results.  For  example,  upon  the  roots  of  teeth  which  have  lost 
their  antagonists  the  pericementum,  deprived  of  its  normal  exercise,  fre- 
quently forms  hypertrophic  growths  of  cementum  upon  the  tooth-roots. 
When  tissues  accustomed  to  mechanical  resistance  due  to  their  anatomi- 
cal forms  are  freed  from  this  resistance,  they  frequently  hypertrophy  in 
the  direction  of  the  accustomed  resistance. 

There  is  a  form  of  cellular  hypertrophy  noted  in  some  pathological 
states  which  should  be  mentioned  in  this  connection,  viz.,  under  some 

Fig.  23. 


"  d  d 

Dog's  hair  encapsulated  in  subcutaneous  tissue :  a,  hair ;  b,  fibrous  tissue  :  c,  proliferating  graiiU' 
lation-tissue  ;  d,  giant  cells.  Preparation  hardened  in  alcohol,  stained  with  Bismark-brown, 
and  mounted  in  Canada  balsam.    X  66.     (Ziegler.) 

forms  or  degrees  of  irritation,  an  increase  in  the  size  of  cells  may  be 
noted  characterized  by  incompleteness  of  formation  ;  the  nuclei  of  cells 
initiate  the  reproductive  process,  but  it  is  incomplete.  The  nucleus 
divides,  but  the  cell-body  fails  of  division,  the  new  nuclei  subdivide,  and 
the  enclosing  cell  increases  in  volume,  forming  a  giant  or  multinucleated 
cell.  These  cells  appear  where  tissue  is  to  be  removed  physiologically, 
as  the  roots  of  deciduous  teeth.  They  are  found  about  foreign  bodies 
which  have  found  entrance  to  tissues,  about  ligatures,  dead  tissues,  etc., 


54  DISTUBBANCES  OF  NUTBITION. 

provided  bacterial  infection  has  not  occurred  and  caused  activ^e  inflam- 
mation. Their  origin  is  probably  from  leucocytes  and  wandering  tissue- 
cells,  which,  having  undergone  this  peculiar  variety  of  reproductive 
change,  forming  large  multinucleated  cells,  and  having  their  phago- 
cytic property  much  increased,  devour  and  remove  many  foreign  sub- 
stances. 

It  is  probable  that  a  similar  condition  exists  about  the  root  of  an 
implanted  tooth.  The  irritation  caused  by  the  presence  of  the  foreign 
body  causes  cell-reproduction,  complete  in  some  cases,  incomplete  in 
others,  the  foreign  substance  being  surrounded  by  a  collection  of  embry- 
onic cells.  Some  foreign  bodies  are  devoured,  others  resist  solution.  In 
the  first  case,  as  soon  as  the  foreign  body  is  disposed  of,  the  cells  take 
on  constructive,  formative  action,  and  are  transformed  into  repair-tissue. 
In  the  second  case,  failing  to  remove  the  intruder,  the  cells  may  acquire 
a  modified  tolerance  of  it,  and  connective  tissue  may  be  developed 
around  it — i.  e.,  it  is  encapsuled. 

TUMOR-FOEM  A  TI  ON . 

Hypertrophy  and  hyperplasia  are  expressions  of  a  degree  of  the 
reproductive  function,  physiological  in  character,  having  in  the  majority 
of  cases  well-defined  causes,  and  serving  an  economic  end  in  the  body. 
There  is  another  form  in  which  there  is  an  excessive  activity  of  the 
cell-property,  the  reproduction  being  wholly  malign  in  character,  its 
products  serving  no  physiological  end ;  on  the  contrary,  threatening 
life  in  the  degree  and  rapidity  of  reproduction.  Such  reproductive 
forms  are  known  as  tumors.  According  to  the  etymology  of  the  word, 
any  swelling  is  a  tumor  {tumeo,  I  swell) ;  but  in  its  pathological 
sense  the  term  is  restricted  to  growths  comprised  under  the  follow- 
ing head  :  "  A  new  formation  of  tissue  possessing  an  atypical  struc- 
ture, not  exercising  any  function  or  service  to  the  body,  and  pre- 
senting no  typical  limit  of  growth."^  This  morbid  reproductive  process 
and  consequent  overgrowth  may  affect  any  of  the  tissues  of  the  body. 
The  growths  may  be  divided  into  two  great  classes  :  first,  those  of  the 
connective-tissue  type — bone,  cartilage,  muscle,  or  ordinary  connective 
tissue  in  any  stage  of  its  development ;  secondly,  those  of  the  epithelial 
type,  arising  from  any  epithelial  structures — that  is,  any  of  the  struc- 
tures which  arise  from  the  epiblast  or  hypoblast  of  the  germinal  layers ; 
the  connective-tissue  tumors  are  those  composed  of  tissues  derived  from 
the  mesoblastic  layer. 

Tumors  may  be  clinically  divided  into  two  groups,  according  to  their 
influence  upon  the  life  of  the  individual  :  first,  benign  tumors,  or  those 
whose  growth  is  not  a  menace  to  life  ;  secondly,  malignant  tumors,  or 

^  Ziegler. 


TUMOR-FORMATION.  55 

those  which  threaten  the  life  of  the  individual  aiFected.  Malignant  and 
benign  tumors  are  found  in  both  classes,  connective  tissue  and  epithelial. 

Tlie  growth  of  a  tumor  is  attended  by  a  saj)ping  of  the  vitality  of  a 
sufferer — the  degree  of  the  debility  produced  being  apparently  in  direct 
ratio  to  the  size  and  the  rajjidity  of  the  growth.  Besides  the  size  and 
the  rapidity  of  development  of  individual  tumors,  another  element  deter- 
mines their  malignancy,  their  jiosition,  aud,  furthermore,  their  occurrence 
in  other  parts,  resulting  in  multiple  tumor-formation.  A  tumor-victim 
acquires  a  peculiar  appearance — a  cachexia,  whose  intensity  and  rapidity 
of  advance  are  directly  dependent  upon  the  degree  of  malignancy. 

Tumors  introduce  no  new  form  of  tissue-element ;  they  are  repro- 
ductions of  the  cells  of  the  tissues  of  the  body.  They  may  have  the 
same  cell-formation  as  the  tissue  from  which  they  spring,  and  are  then 
called  homologous  tumors  ;  or  they  may  have  a  different  histological 
structure  from  the  tissue  in  which  they  are  found,  being  then  called 
heterologous  tumors.  For  example,  a  bony  tumor  growing  from  bone 
would  be  homologous  ;  a  cartilaginous  tumor  growing  from  gland-tissue 
would  be  heterologous. 

Causes. — The  causes  of  tumor-formation  are  unknown  ;  it  has  been 
believed  that  their  growth  is  due  to  parasites  ;  this  however  has  not  been 
proved.  A  certain  proportion  of  tumor-formations,  7-14  per  cent.,' 
appear  to  be  caused  by  traumatic  injury  ;  as,  for  example,  in  cases  of 
mammary  tumor  a  history  of  a  blow  or  fall  may  be  at  times  obtained. 

Long-continued,  sluggish  inflammation  appears  to  be  causative  of 
tumor-formation  in  an  unknown  percentage  of  cases.  A  chronic  irritation 
of  certain  portions  of  the  body,  such  as  the  junction  between  the  mucous 
and  skin  surfaces  of  the  lip,  the  sides  of  the  tongue,  etc.,  is  a  frequent 
antecedent  to  their  formation.  Ziegler  gives  a  reasonable  ex])lanation 
of  the  origin  of  certain  epithelial  tumors  in  organs  which  are  under- 
going atrophy  ;  for  example,  in  advanced  age  the  connective  tissue  of 
the  body  is  undergoing  atrophy  and  there  is  relaxation  of  its  strata  ;  the 
epithelium  of  the  surface  (or  of  glands),  still  possessed  of  its  power  of 
reproduction,  proliferates  and  invades  the  connective  tissue,  producing 
cancer. 

Tumor-formation  consists  in  the  reproduction  of  the  cells  of  one  or 
more  tissues,  and  in  the  growth  thus  formed  bloodvessels  are  developed. 
Tumors  do  not  contain  nerves.^  Their  blood-supply,  however,  is  gen- 
erous, so  that  for  long  periods  a  superabundance  of  nutritive  material 
is  carried  to  them ;  but  after  a  variable  period,  depending  upon  the 
type  of  growth,  the  nutritive  supply  becomes  disordered  and  degenera- 
tions occur. 

About  the  more  slowly  developing  tumors  a  condensation  of  connec- 

'  Ziegler.  ^  Green's  Pathology  and  Morbid  Anatomy,  8th  ed. 


56  DISTUBBANCES  OF  NUTBITION. 

tive  tissue  occurs  in  many  cases,  forming  a  distinct  limiting  wall  or  cap- 
sule from  which  the  tumor  may  be  enucleated. 

The  two  great  classes  of  tumors,  those  of  mesoblastic  and  those  of 
epi-  and  hypoblastic  origin,  may  be  subdivided  into  orders  according  to 
their  histological  peculiarities. 

Class  Onb.^ 
tumoes  of  mesoblastic  tissues  : 

Order   One. 
Tumors  of  mature  connective  tissue. 

Bony  tumors,  or  Osteoma. 
Cartilaginous  tumors,  or  Chondroma. 
Fibrous  tumors,  or  Fibroma. 
Fatty  tumors,  or  Lipoma. 
Mucous  tumors,  or  Myxoma. 
Lymphoid-tissue  tumors,  or  Lymphoma. 

Order  Two. 
Tumors  of  the  embryonic  connective  tissues  : 

The  fleshy  tumors,  or  Sarcoma. 

Order   Three. 
Tumors  of  the  higher  tissues  : 

Tumors  of  muscle,  or  Myoma. 

Tumors  of  nerves,  or  Neuroma. 

Tumors  of  bloodvessels,  or  Angioma. 

Tumors  of  lymphatic  vessels,  or  Lymphangioma. 

Class  Two. 
tumors  of  epiblastic  and  hypoblastic  tissues  : 

Papilla  of  skin  and  of  mucous  membrane,  or  Papilloma. 

r  Adenoma. 
Tumors  of  glandular  tissue  |  ^^^^.^^^^_ 

A  separate  class  of  tumors  includes  congenital  mixed  tumors,  or 
Teratomata.  The  tumors  of  epiblastic  and  hypoblastic  type  are  some- 
times called  Epitheliomata,  for  epithelial  tissue  is  their  characteristic  his- 
tological structure. 

Malignant  tumors  are  found  in  both  of  the  great  classes,  mesoblastic 
and  epi-  and  hypoblastic.  Carcinoma  represents  the  type  of  malignancy 
1  Modified  from  Green's  Pathology,  p.  148. 


TUMOR-FORM  A  TION. 


bl 


ill  the  epithelial  tumors.  The  sarcomata  are  the  malignant  tumors  of 
the  connective-tissue  type. 

Tumors  are  rarely  composed  of  but  one  type  of  tissue ;  several  types 
may  be  present,  the  tumor  receiving  its  name  from  the  tissue  predom- 
inatino-.  When  the  distinguishing  feature  of  a  tumor  is  two  predomin- 
ating tissues,  the  tumor  is  given  a  compound  name  ;  as,  for  example, 
when,  in  a  sarcomatous  growth,  numerous  large  multinucleated  cells  char- 
acteristic of  bone-marrow  are  found,  it  is  called  a  myeloid  sarcomatous 
tumor.  When  fibrous  and  sarcomatous  tissues  are  distinguishing  feat- 
ures the  tumor  is  called  a  fibro-sarcoma. 

Since  the  malignancy  of  a  tumor  is  due  primarily  to  the  size  and  the 
rapidity  of  its  growth,  it  is  clear  why  sarcomata  are  more  malignant 
than  fibromata,  and  why  some  forms  of  sarcoma  are  more  malignant 
than  others.     To  illustrate  : 

Begin  observation  at  the  indifferent  stage  of  connective-tissue  de- 
velopment, when  connective-tissue  cells  have  first  divided,  reproduced ; 

Fig.  24. 


Porciue  embryo:  ct,  embryonic  couuective  tissue  of  mesoblast.    2^  cm.  X  250. 


the  tissue  produced,  seen  in  granulation-tissue  and  in  the  embryo,  is  at  the 
indifferent  stage,  as  .seen  in  section  of  the  embryonic  jaw  (Fig.  24). 

Mesoblastic  cells  at  this  early  period  are  in  an  indifferent  stage  ;  some 
of  the  cells  shown  in  the  figure  will  form  bloodvessels,  others  will  l)ecome 
bone-corpuscles,  others  will  form  fibrous  and  others  muscular  tissue. 
This  structure  has  its  analogue  among  tumors  in  a  soft,  fleshy,  rapidly 
growing  growth,  called  the  round-celled  sarcoma.  As  cells  expend  their 
vital  energy  in  three  ways  (nutritive,  functional,  and  reproductive  ac- 
tivity), the  embryonic  cells  of  such  a  growth  may  expend  their  energy 
in  nutrition  (growth),  and  will  then  grow  out  of  the  indifferent  stage 
into  a  more  mature  form  of  connective  tissue,  the  ultimate  form  of  one 
type  being  a  fibre,  an  embryonic  round  cell  undergoing  a  series  of  form- 


58 


DISTURBANCES  OF  NUTRITION. 


changes  from  a  small  round  cell  to  a  long  fibre  (Fig.  25).  The  growth 
may  cease  at  any  stage  of  this  form-change,  the  tumor  composed  of  such 
cell-forms  receiving  a  corresponding  name.  The  embryonic  connective- 
tissue  tumors,  as  stated,  are  called  sarcomas,  the  form  of  the  cells  com- 
posing them  giving  them  a  qualifying  title. 

In  Fig.  25  are  represented  the  stages  of  development  of  a  connec- 
tive-tissue fibre  from  a  round  cell.     If  growth  cease  at  stage  1,  and  the 


Fig.  25. 


1  2 

®    ® 


cell-energy  thereafter  expend  itself  in  reproduction,  a  rapidly  growing- 
tumor  composed  of  small  round  cells  is  formed — a  small  round-cell 
sarcoma,  markedly  malignant.  If  the  cells  expend  a  portion  of  energy 
in  growth  of  cell-size,  a  large-cell  sarcoma  is  formed,  less  malignant 
than  the  former.  If  the  cells  expend  a  portion  of  their  energy  in  form- 
ing intercellular  substance  (reproduction),  malignancy  is  less  active. 
So  the  spindle-forms,  3  and  4,  represent  less  rapid  reproduction  and  lesser 
malignancy  than  1  and  2,  although  the  form  4,  which  should  be  of  less 
rapid  reproduction  than  3,  because  of  more  mature  organization,  is  fre- 
quently more  malignant,  because  less  intercellular  substance  is  formed, 
as    shown  in  Figs.  26  and  27,  the  energy  represented  in  that  process 

Fia.  27. 


Ftg.  26. 


Small  spindle-celled  sarcoma  (from  a 
tumor  of  the  leg).    X  200. 


Large  spindle-celled  sarcoma.  To  the  left  the  cells  have 
been  separated  by  teasing,  so  that  their  individual 
forms  are  apparent ;  to  the  right,  they  are  In  their 
natural  state  of  apposition,  such  as  would  be  seen  in 
a  thin  section  of  the  tumor.    (Virchow.) 


being  used  up  in  reproduction.  The  nearer  the  approach  to  the  mature 
form,  (6,  Fig.  25),  the  slower  the  growth  of  the  tumor,  which,  w^hen 
composed  of  tissue  of  this  type,  loses  its  fleshy  (sarcomatous)  appearance 
and  becomes  fibrous,  and  is  hence  called  fibroma. 

When  a  sarcoma  begins  its  growth  from  bone  its  histological  char- 
acter is  frequently  modified  (Fig.  28).     It  contains  large  marrow-cells 


TUMOR-FORMA  TION. 


59 


which  have  undergone  incomplete  reproduction,  forming  giant  multi- 
jiueleated  cells ;  this  is  a  common  form  of  tumor  emerging  from  the 
sockets  of  teeth.     Some  of  the  cells  of  a  sarcomatous  growth  may  go  on 


Fig.  28. 


Myeloid  epulis  from  lower  jaw.    a,  multinucleated  giant  cells;  6,  oval  cell.    X  265.    (Pepper.) 


to  maturity,  while  others  remain  at  some  stage  of  their  developmental 
career.  Malignancy  will  be  modified  according  to  the  amount  of  mature 
tissue  formed. 

Epithelial  Tumors. — Growths  arising  from  epi-  or  hypoblastic  tis- 
sues may  be  benign  or  malignant.  AVhat  are  called  the  adenomata  mav 
be  taken  as  the  type  of  the  benign  epithelioma ;  that  is,  comparatively 
benign.  They  present  all  of  the  characters  of  typical  glandular  tissue  : 
numerous  acini  lined  with  epithelial  cells  and  surrounded  by  connective 

Fig.  29. 


Adenoma  of  the  breast:  a,  group  of  glandular  acini ;  6,  fibrous  stroma;  c.  cells  broken  away  from 
their  attachment.     X  265.    (Pepper.) 


tissue  (Fig.  29).     Tumors  of  this  type  may  lose  their  comparative  be- 
nignancy  and  become  of  the  succeeding  epithelial  type. 

Carcinomata. — These  are  growths  arising  from  pre-existing  epithelial 


60 


DISTURBANCES  OF  NUTBITIOK 


tissue,  which  possess  the  characteristics  of  epithelium  developing  with- 
out the  limitations  of  a  basement-membrane.     Beginning  upon  a  skin, 

or  mucous  surface,  or  in  a  gland,  the  re- 
produced epithelial  cells  are  not  sharplj 
marked  off  from  the  connective  tissue  by 
a  limiting  membrane,  but  gaining  en- 
trance to  the  alveoli  of  connective  tissue, 
they  proliferate  there,  find  their  way  inta 
lymphatic  vessels  and  lymphatic  glands, 
and  reproduce  epithelial  growths  in  such 
places  of  lodgement,  so  that  a  tumor  hav- 
ing its  origin  in  one  part  may  give  rise  to 
tumors  in  other  parts  of  the  body  (Fig. 
30). 

Like  the  connective-tissue  tumors,  types 
of  carcinoma  diifer  as  to  rapidity  of  growth 
in  their  original  situation  and  in  the  degree 
of  transference ;  these  factors  determine 
their  malignancy.  Tumors  of  the  sar- 
coma group  may  also  give  rise  to  growths 
in  other  parts,  the  tumor-cells  being  car- 
ried thence  by  lymph-vessels  or  bloodvessels. 

After  a  period,  tumors  frequently  suffer  such  interference  with  their 
nutrition  that  degeneration  occurs  in  them. 

After  removal,  some  varieties  of  tumors,  both  those  which  infiltrate 
surrounding  tissues  and  those  which  are  metastatic  (or  transferred  from 
the  original  to  other  sites),  show  a  tendency  to  recurrence  ;  that  is, 
removal  does  not  effect  a  cure,  and  the  tumor  may  upon  reappearance 
assume  another  and  a  more  malignant  character. 

Epithelial  tumors  never  become  tumors  of  the  connective-tissue 
type ;  and,  vice  versa,  connective-tissue  tumors  cannot  become  epithelial 
tumors.  The  distinction  formed  between  epiblast  and  mesoblast  in  the 
embryo  is  maintained  throughout  life. 


Section  through  an  aggregation  of 
very  young  cancer-cells,  lodged 
like  an  embolus  within  a  capillary 
of  the  liver.  The  parent  growth 
was  an  adenocarcinoma  of  the 
stomach.  Preparation  stained  with 
hsematoxylin.    X  300.    (Ziegler.) 


INFLAMMATORY    DEGENERATION. 

If  the  degree  of  irritation  causing  an  increased  activity  of  the  repro- 
ductive function  be  exceeded,  the  entire  nutritive  balance  of  a  part  be- 
comes disturbed  in  a  violent  manner;  the  vascular  disturbance  accom- 
panying hypertrophic  processes  becomes  much  exaggerated  in  the 
tissues  in  the  area  involved.  The  nutrition  of  the  cells  of  the  part 
appears  to  be  in  abeyance,  and  vitality  in  them  ceases  ;  the  protoplasm 
has  lost  its  character,  and  in  the  affected  area  a  collection  of  embryonic 
cells  is  found ;  this  is  the  condition  described  in  the  next  chapter  under 


HYPOy  UTRITIOX—DEGENERA  TIOXS.  6 1 

the  head  of  inflammation.     The  final  stage  oif  overstimulation  has  been 
reached — death  by  overwork. 

Hyponutrition. 

If  the  nutritive  balance  be  disturbed  upon  the  minus  side,  it  amounts 
to  the  application  of  a  sedative  influence  in  varying  degrees.  As  in  the 
cases  of  hypernutrition,  the  stages  or  degrees  of  hyponutrition  are 
intimately  associated  with  the  conditions  of  the  vascular  supply — its 
quality  and  its  quantity.  The  first  stage  of  hyponutrition  is  comprised 
in  an  atony,  a  lessened  activity  of  the  vital  processes  of  a  part.  Cell 
chemistry  is  disordered,  less  oxidation  occurs,  hence  a  lessened  heat- 
production  ;  the  function  of  the  cell  is  diminished ;  if  secretory,  its  se- 
cretion is  lessened ;  if  muscular,  the  cell  has  lessened  contractility  ;  the 
relations  between  nutrition  and  waste  are  disturbed ;  the  part  becomes 
physiologically  wearied  sooner  than  usual. 

ATROPHY. 

Causes. — If  the  disturbance  in  the  nutritive  supply  be  continued  or 
be  in  more  marked  degree,  the  nutritive  processes  in  cells  become  dis- 
ordered, so  that  more  cell-substance  is  broken  down  than  is  replaced  by 
pabulum  ;  that  is,  waste  exceeds  repair,  and  the  part  aifected  becomes 
diminished  in  size — /.  e.,  becomes  atrophied.  The  atrophy  may  occur 
either  because  the  food-supply  is  insufficient,  or  because  the  cell  has 
undergone  such  change  that  it  is  not  able  to  use  its  nutriment  when 
present  in  proper  quantity  and  quality.  Atrophy  is,  however,  more 
often  traceable  to  an  improper  food-supply,  or  an  excess  of  waste,  than 
from  any  clearly  made-out  fault  in  tissues.  A  common  source  of  insuf- 
ficient food-supply  is  interference  with  the  vascular  supply  to  a  part. 
It  may  be  any  of  the  causes  (see  Chapter  V.)  which  lessen  the  size  of 
the  artery  supplying  a  part. 

Disuse  of  a  part  may  be  followed  by  a  diminution  of  its  vitality  : 
it  becomes  atonic,  and  then  atrophies.  The  atrophy  is  proportionate  to 
the  extent  of  the  disease.  Atrophy  of  organs  may  be  a  part  of  the 
cycle  of  life ;  as,  for  example,  atrophy  of  the  thymus  gland  in  children, 
and  atrophy  of  the  mammary  gland  in  the  female  after  the  menopause. 
INIany  atrophies  of  this  type  are  properly  termed  resorptions  ;  as,  for 
example,  in  the  thymus  gland  when  the  entire  gland  is  removed.  The 
loss  of  the  roots  of  deciduous  teeth  and  the  loss  of  the  alveolar  process 
after  teeth  have  been  lost  are  examples  of  tissue-loss  through  resor])tion. 

D  ECx  EN  ER  ATIO  XS . 

If  the  nutritive  balance  be  disturbed  through  intrinsic  defect  of  cells, 
or  through  a  further  disturbance  in  the  character  or  the  amount  of  the 


62 


DISTURBANCES  OF  NUTRITION. 


food-supply,  the  vitality  of  the  cells  undergoes  more  marked  change. 
The  character  of  the  cell  itself  becomes  altered,  its  chemical  pro- 
cesses are  markedly  deranged,  and  changes  in  the  cell-substance 
itself  may  be  noted.  The  function  of  a  part  is  impaired  and 
soon  ceases  entirely.  This  is  a  cell-degeneration  proper.  Such  pro- 
cesses are  usually  accompanied  by  shrinking  in  the  size  and  diminution 
of  the  number  of  cells  in  a  part ;  that  is,  degeneration  and  atrophy  are 
processes  commonly  associated.  In  an  actual  degeneration  the  proto- 
plasm itself  becomes  altered  in  character ;  the  proteids  of  which  it  is 
composed  are  in  part  transformed  into  other  substances. 

There  is  another  type  of  degeneration  in  which  the  protoplasm  does 
not  seem  to  have  changed  its  chemical  character,  and  yet  foreign  sub- 
stances make  their  appearance  in  tissue  and  atroj^hy  of  its  cellular  ele- 
ments follows. 

True  Degeneration. — The  first  type  of  cellular  degeneration  is  that 


Fig.  31. 


<W0My'^'- 


Cloudy  swelling  of  kidney  epithelium:  a,  normal  epithelium;  &,  epithelium  beginning  to  be 
cloudy  ;  c,  advanced  degeneration ;  d,  cast-off  degenerated  epithelial  ceils.  From  a  preparation 
which  had  been  treated  with  ammonium  chromate.    X  600.    (Ziegler.) 


called  cloudy  swelling.  The  contents  of  a  cell  become  markedly  granu- 
lar, hence  the  name  of  the  condition,  granular  degeneration,  and  the 
cell  increases  in  size.  "  This  change  is  to  be  regarded  as  a  disorganiza- 
tion of  the  cell-protoplasm  following  the  absorption  of  liquid  into  its 
substance,  and  leading  to  a  partial  separation  of  its  solid  and  liquid  con- 
stituents.    The  cell  may  recover  ;■  but  there  is  often  complete  destruc- 


DEGENERATIONS.  63 

tion,  the  cell  ultimately  breaking  down  into  finely  granular  fragments."^ 
This  is  the  parenchymatous  degeneration  found 
in  continued  fevers. 

"  It  mav  be  regarded  as  the  first  step  toward  ,  -  ^ ''-' 

fatty  metamorphosis."  " 

Patty  Degeneration. — Fatty  degeneration  is 
a  condition  in  which  an  accumulation  of  fat  is 
found  in  the  substance  of  cells  as  the  result  of 
partial  decomposition  of  cell-substance  itself. 

Causes. — Fatty    degeneration    results    from      %^ff  w-^^IK-" 
great    disturbance    in   the   nutritive    balance    of    Muscular  tissue  of  the  heart 
cells  ;  that  is,  the  cause  of  fatty  degeneration  is      ^^'"""^  ^  ^•'^^^  f  ^Z""'^  ^>'- 

'  '  JO  phoid  fever) :  the  fibres  are 


a  higli    degree   of  disturbance  of  cell-nutrition.      granular,  the  nuclei  ob 

scured,   and 
lost.     X  400, 


''  The  larger  the  amount  of  cell-albumin  replaced      ''''''''•  "^<^  '^^  ^*"^*'°'' 


by  fat,  the  nearer  is  the  whole  cell  to  death."  '^ 
Depressed  vitality  is  always  the  proximate  cause.  It  may  be  produced 
by  improper  food-supply  and  by  changes  in  the  vital  powers  of  cells, 
or  it  may  be  an  expression   of  the  natural  decadence  of  cells. 

Disuse  of  a  part  which  has  normally  an  active  physiological  func- 
tion is  not  infrequently  followed  by  a  degeneration  of  cell-substance  and 
an  associated  atrophy  of  the  part. 

Mechanical  interference  with  the  blood-supply  of  a  part  is  a  prolific 
source  of  fatty  degeneration  of  its  cells.  When  the  walls  of  vessels 
have  undergone  the  changes  known  as  atheroma  and  calcareous 
degeneration  (which  see),  the  arterial  (food)  supply  to  the  tissues 
involved  becomes  much  impeded.  This  change,  occurring  usually  at 
a  time  of  life  when  cell-vitality  is  on  the  wane,  is  followed  by  faulty 
metabolism  in  the  cell ;  there  is  not  that  complete  chemical  interchange 
which  occurs  in  normal  metabolism,  and  degeneration  occurs.  AVIien  the 
coronary  arteries  of  the  heart  become  atheromatous  fatty  degeneration 
of  the  heart-muscle  follows. 

When  the  blood  is  deficient  in  quality,  as  in  the  several  forms  of 
anfemia,  particularly  pernicious  anaemia,  fatty  degeneration  and  atrophy 
of  organs  may  result  in  consequence  of  the  faulty  nutrition. 

Fatty  degeneration  is  one  of  the  consequences  of  faulty  oxklation  in 
tissues,  which  explains  its  occurrence  in  the  above-mentioned  conditions, 
and  it  in  turn  lessens  the  oxidizing  poM'er  of  cells,  the  resulting  cellular 
debility  interfering  with  such  processes  as  regeneration  or  the  re})aii'  of 
tissues. 

Fatty  degeneration  is  the  fate  of  nerve-fibres  which  have  been  sev- 
ered from  connection  with  their  nerve-centre. 

^  Ziegler's  General  Patholnrpj,  1895. 

^Green's  Pathology  and  ^Forbid  Anatomy,  1895.  *  Ibid. 


64  DISTURBANCES  OF  NUTRITION. 

In  addition  to  the  fatty  metamorphosis  which  occurs  in  tissue- 
cells  as  the  result  of  faulty  metabolism,  this  change  of  cell-albu- 
min also  occurs  in  other  pathological  states ;  for  example,  the  cells  in 
certain  inflammatory  effusions  undergo  fatty  metamorphosis. 

Tlie  process  occurs  in  the  cells  of  tumors  when  the  growth  of  their 
vascular  supply  does  not  keep  pace  with  the  volume  of  the  tumor. 

A  peculiar  change  sometimes  takes  place  in  portions  of  tissue  which 
have  suffered  fatty  degeneration,  the  change  affecting  particularly  parts 
which  have  degenerated  in  consequence  of  the  presence  of  the  bacillus 
tuberculosis.     The  presence  and  proliferation  of  the  bacillus  in  tissues 

appear  to  be  attended  by  phagocytic 

F^f^- S3-  action   (see   Chapter  III.)  upon   the 

®-^ -—?„"' V~;5:^'^p,  part  of  the  cells  about  them.     The 

■7^-0"--  -__-  ^^^»^  irritation    resulting  from   the    action 

®^  '  '      "^  „  -         of  the  bacillus  causes  incomplete  re- 

IjT^S'^r,       '  n^       productive  activity  in  the  cells,  and 

/f^"    f^    f'\      ,  I    X         "  oJ     multinucleated  cells  are  formed.    The 

f^    -   '  V  ^ 

f^     =             ^i"    /   .   "  bacilli  are  taken  into  the  bodies  of 

"^i^g  ^                 -^^j^^^iM  these  cells,  the  irritation  set  up  caus- 

b^^-f^^^^S^^"'  iug  (Fig-  33)  an  emigration  of  leuco- 

^  ,     -    ,     .^,f"^  -    .    n  ,r       .V,  cytes  from  the  adjacent  vessels  which 

Tubercle  bacilli  in  giant-cell  (from  tuber-         -^  *' 

cuiosis  of  horse).  X  600.  (Cheyne.)  occupy  the  coiiiiective-tissue  spaces  ; 

the  accompanying  effusion  solidifies, 
and  in  the  affected  spot  is  formed  what  is  termed  a  tubercle.  The  cells 
after  a  period  may  undergo  fatty  degeneration,  and  following  this  the 
mass  is  transformed  into  a  cheesy  substance,  in  consequence  of  which 
the  process  is  called  caseation. 

In  apoplectic  effusions  into  the  brain-substance  the  effused  blood  and 
part  affected  undergo  fatty  degeneration  and  caseation. 

It  not  infrequently  happens  that  in  these  caseous  masses  calcium 
salts  are  deposited.  At  times  the  entire  mass  may,  from  some  unknown 
cause,  excite  active  inflammation. 

Fatty  Degexeration  of  Vessels. — The  occurrence  of  fatty 
degeneration  of  the  heart-muscle  due  to  obstruction  in  the  coronary 
arteries  has  been  alluded  to.  A  similar  condition  may  occur  in  the 
muscle-fibres  of  the  middle  coat  of  bloodvessels.  It  occurs  most  fre- 
quently in  the  internal,  the  endothelial  coat,  or  the  tunica  intima  of 
vessels.  Droplets  of  fat  are  formed  in  the  endothelial  cells  lining  the 
vessels.  "  In  the  smaller  arteries  the  fatty  degeneration  is  more  liable 
to  affect  the  external  coat."  ^  In  some  forms  of  nephritis  (Bright's  dis- 
ease) fatty  degeneration  affects  the  endothelial  cells  of  the  capillary 
vessels,  leading  to  their  rupture. 

^  Green's  Pathology  <ind  Morbid  Anatomy. 


DEGENERATIOXS.  65 

Mucoid,  Colloid,  and  Hyaline  Degeneration. — The  albumin  of 
cells  may  undergo  other  ehemical  ehanges  than  transformation  into 
fatty  substances ;  they  may  undergo  mucoid,  colloid,  or  hyaline  trans- 
formation. The  causes  of  the  degeneration  are  not  made  out.  The 
function  of  the  part  affected  is  destroyed. 

Lardaceous  Degeneration. — This  type  of  degeneration  is  known 
as  amyloid,  albuminous,  or  Avaxy.  The  formation  of  the  material  from 
which  this  condition  derives  its  name  is  preceded  by  an  unknown  type 
of  degeneration  of  the  cells  of  the  part  affected.  The  degenerative 
processes  appear  to  be  the  result  of  long-continued  suppuration  due 
usually  to  tubercular  diseases.  In  the  connective  tissue  about  the 
degenerated  cells  a  substance  akin  to  albumin  is  deposited,  which  causes 
swelling  and  a  pseudo-hypertrophy  of  the  organ  affected.  The  substance 
gives  a  reaction  with  iodin  resembling  that  of  starch,  hence  the  name 
amyloid  {ami/hun,  starch).  It  may  affect  any  organ  of  the  body.  It 
usually  appears  first  in  the  connective  tissue  lying  between  the  inner 
and  middle  coats  of  small  arteries.  The  swelling  caused  by  the  infiltra- 
tion markedly  lessens  the  calibre  of  the  vessels  and  diminishes  the 
nutritive  supply  of  the  parts  supplied  by  the  artery,  which  may  lead 
to  fatty  degeneration  and  atrophy  of  the  insufficiently  nourished 
parts. 

Calcareous  Degeneration, — This  condition  must  be  clearly  distin- 
guished from  ossific  or  bone-forming  changes  which  occur  in  tissues. 
In  bone-formation  there  is  a  constructive  process  in  which  cells  build  a 
definite  type  of  formed  material.  In  what  is  called  calcareous  degen- 
eration there  is  a  deposit  of  calcium  salts,  mainly  the  phosphate  and 
carbonate.  In  bone-formation  the  lime  salts  are  combined  in  a  definite 
manner  with  an  albuminous  basis  (see  Calco-globulin).  The  phosphates 
and  carbonates  of  calcium  and  the  carbonate  of  magnesium  are  held  in 
solution  in  the  serum  of  the  blood  by  virtue  of  the  carbon  dioxid  in 
the  blood.  It  is  believed  that  the  deposit  of  calcium  salts  in  a  tissue  is 
more  than  a  mere  precipitation,  and  that  calcification  results  from  the 
combination  of  the  salts  with  an  albuminous  base  and  with  fatty  acids. 
These  deposits  occur  in  tissues  which  are  in  a  degenerative  or  dying 
state.  They  follow  frequently  as  a  secondary  state  upon  fatty  degen- 
eration, caseation,  and  hyaloid  degeneration  of  tissues,  particularly  of 
connective  tissues.  A  similar  deposit  occurs  in  the  affected  joints  in 
gout,  when  sodium  biurate  is  deposited  in  the  affected  tissues.  This  is 
particularly  notable  in  the  walls  of  bloodvessels  which  have  suffered 
previous  degeneration. 

The  changes  which  pronounced  degeneration  or  death  of  cells  brings 
about  in  tissues  appear  to  create  an  affinity  between  such  substances  and 
the  calcium  salts  of  the  blood,  so  that  they  form  intimate  compounds. 


66  DISTURBANCES  OF  NUTRITION. 

The  deposits  may  be  in  the  cells  themselves,  as  well  as  in  the  intercellu- 
lar substance.  They  affect  particularly  the  white  fibrous  connective 
tissues.  What  appears  to  be  a  cardinal  principle  in  these  calcic  deposits, 
is  the  formation  of  substances  during  or  following  degenerative  changes 
in  parts  having  a  sluggish  circulation,  which  substance  renders  insoluble 
the  calcium  salts  held  in  solution  by  the  carbon  dioxid  of  the  blood,  or 
possess  a  stronger  chemical  affinity  for  the  salts  than  the  carbon  dioxid 
which  holds  them  in  solution. 

Calcification  or  Aeteeies. — In  or  during  the  series  of  nutri- 
tional disturbances  associated  with  senility,  the  degeneration  of  tissues 
accompanying  old  age,  calcareous  deposits  may  occur  in  the  middle  coats 
of  arteries,  transforming  these  normally  elastic  tubes  into  rigid  tubes  of 
lessened  calibre.  Such  arteries  cannot  perform  their  normal  function  in 
regulating  the  blood-current,  and  parts  supplied  by  them  suffer  more  or 
less  nutritive  disturbance  and  in  some  cases  actual  death.  Calcareous 
areas  frequently  form  in  such  portions  of  arteries  as  have  suffered  from 
an  inflammatory  degeneration  of  the  tissues  of  the  deeper  layer  of  the 
inner  arterial  tunic  (i.  e.,  atheroma). 

NECEOSIS. 

When  the  depression  of  vital  activities  due  to  disturbance  of  the 
nutritive  balance  becomes  more  marked  than  those  grades  productive 
of  atrophy  and  degeneration  of  a  part,  the  vital  processes  of  the  cell 
are  paralyzed — it  dies  from  starvation,  the  condition  being  called  necro- 
sis, from  neh'os,  dead. 

Causes. — The  conditions  which  bring  about  a  cessation  of  vitality  in 
the  cells  of  tissues  may  be  grouped  under  two  heads  •}  1st.  Interference 
with  the  supply  of  nutritive  material ;  2d.  Destruction  of  the  vital 
activity  of  cellular  elements. 

Class  I. — Necrosis  arising  out  of  the  first  group  is  caused  by  ob- 
struction of  the  vascular  supply,  through  occlusion  of  arteries,  veins,  or 
capillaries. 

1st.  Obstruction  of  the  arteries.  If  from  any  cause — surgical  ligation 
of  an  artery,  pressure  upon  it  by  effusions  or  new  growths,  degeneration 
or  affections  of  the  arterial  walls,  the  presence  of  an  embolus  or  throm- 
bus (Chapter  Y.) — the  flow  of  blood  to  a  part  is  arrested,  the  nutritive 
supply  ceases  and  the  cells  dependent  upon  that  vessel  perish.  If  the 
part  receive  a  collateral  arterial  supply,  the  cells  may  retain  their 
vitality,  although  if  this  supply  be  inadequate  they  are  in  danger  of 
degeneration  and  atrophy.  This  will  explain  the  greater  relative  fre- 
quency of  extensive  necrosis  of  the  lower  jaw,  as  compared  with  necro- 
sis affecting  the  ujjper  jaw,  the  lower  jaw  being  supplied  mainly  by  one 

^  Green. 


NECROSIS.  67 

large  arterial  trunk,  while  in  the  upper  jaw  there  is  a  freely  anastomos- 
ing circulation. 

2d.  Obstruction  of  the  veins.  If  the  entire  venous  outlet  of  a  part 
be  obstructed,  there  is  not  that  removal  of  waste-products  necessary  to 
the  life  of  cells ;  moreover,  access  of  nutritive  material  is  prevented 
and  the  parts  die. 

3d.  Obstruction  of  the  capillaries.  Complete  obstruction  of  the 
capillary  supply  to  a  part  is  followed  necessarily  by  a  cessation  of  nutri- 
tion in  the  part ;  consequently  necrosis  results.  For  example,  when  an 
inflammatory  effusion  occurs  between  the  surface  of  a  bone  and  the  peri- 
osteum, the  capillaries  are  torn  from  their  attachment ;  and  if  the  condi- 
tion be  prolonged,  necrosis  of  the  underlying  bone  results.  When  the 
effusion  occurs  outside  the  periosteum  its  pressure  may  cause  occlusion 
of  the  capillaries  of  the  part.  The  interference  with  the  nutritive  supply 
may  be  due  to  a  lack  of  force  with  which  the  blood  is  propelled,  owing 
to  insufficient  action  of  the  heart.  Necrosis  is  not  infrequently  due  to 
the  violence  and  continuance  of  the  inflammatory  process  in  a  part. 
Coagulation  of  the  blood  in  the  capillaries  of  a  part  occludes  the  circu- 
lation and  death  results. 

Class  II. — Destruction  of  the  vital  activities  of  cells  may  be  caused 
by  any  of  the  physical  forces  or  by  the  action  of  chemical  agents, 
including  among  the  latter  the  poisonous  substances  formed  through 
the  action  of  bacteria. 

Injuries,  blows,  excessive  heat  or  cold,  the  passage  of  powerful  elec- 
tric currents,  are  all  influences  which  directly  injure  or  permanently 
destroy  vital  activities  of  cells.  The  application  of  chemical  agents 
which  so  act  upon  cell-substance  as  to  change  its  character  produces 
necrosis.  While  this  is  particularly  true  of  such  substances  as  powerful 
acids  and  alkalies,  which  immediately  destroy  cell-integrity,  it  is  also 
true  of  milder  agents  acting  for  longer  periods.  Certain  poisons,  par- 
ticularly those  of  bacterial  origin,  paralyze  the  vital  activities  of  cells 
and  necrosis  results. 

The  occurrence  or  non-occurrence  or  the  liability  to  necrosis  will 
largely  depend  upon  the  degree  of  vital  energy  of  cells  prior  to  the 
action  of  the  active  causes  of  necrosis.  Parts  debilitated  from  any 
cause  are  more  liable  to  necrosis  than  those  which  have  suffered  no 
debility.  A  part  chronically  ill-nourished  subjected  to  the  causes  pro- 
ducing degenerations  is  liable  to  suffer  necrotic  changes,  for  the  several 
degenerations  and  atrophy,  as  shown  in  Fig.  22,  are  but  successive 
stages  leading  to  necrosis. 

When  a  tissue  undergoes  death  as  the  result  of  the  infliction  of  an 
injury  the  process  is  called  necrosis  per  se,  to  distinguish  it  from  the 


68  DISTURBANCES  OF  NUTRITION. 

form  of  death  which  occurs  in  a  descending  scale,  which  process  is 
called  necrobiosis. 

A  necrosed  part  acts  as  an  irritant  to  the  tissues  about  it,  inaugurat- 
ing an  inflammatory  reaction  which  marks  off  the  dead  from  the  living 
parts.     The  dead  part  is  sequestred,  and  hence  is  called  a  sequestrum. 

Coag-ulation-necrosis.  —  When  a  dead  tissue  contains  coagulable 
material  and  the  necessary  ferments  (Chapter  Y.)  the  parts  undergo 
coagulation.  The  cells  and  parts  about  become  solidified  ;  the  cells 
lose  their  nuclei  and  do  not  stain  as  usual. 

Liquefaction-necrosis.  —  When  the  necrosed  parts  are  saturated 
with  lymph  the  dead  part  breaks  down  and  liquefies. 

Dry  Gangrene. — When  parts  have  died  as  the  result  of  stoppage  of 
circulation  and  the  access  of  fluids  is  prevented,  the  dead  part  may 
undergo  a  species  of  mummification. 

Moist  Gangrene. — When  the  organisms  of  putrefactive  fermenta- 
tion gain  access  to  a  necrotic  part  they  break  down  the  dead  tissues, 
with  the  formation  of  products  described  in  Chapter  III.  The  forma- 
tion of  such  gases  as  hydrogen  sulfid,  HgS,  hydrogen  phosphid,  PHg, 
and  ammonium  sulfid,  (^114)28,  gives  the  offensive  odor  to  gangrenous 
parts.  The  amount  of  water  necessary  for  the  development  of  putre- 
factive organisms  is  not  present  in  dry  gangrene,  hence  putrefactive 
decomposition  is  absent  or  long  delayed  in  this  condition. 


CHAPTER  V. 

DISTURBANCES  OF  THE  VASCULAR  SYSTEM. 

Ever  since  the  physical  nature  of  the  circulatory  apparatus  was 
pointed  out  by  William  Harvey  in  1628,  disturbance  of  the  equilibrium 
of  the  circulation  has  been  held  to  have  a  close  relationship  with  the 
process  of  nutrition.  The  sum  and  substance  of  contemporary  view  of 
this  matter  is  that  an  increase  in  the  flow  of  blood  to  a  part  means  an 
increase  of  nutritive  material  in  the  part ;  that  is,  increased  circulation 
means  hypernutrition.  We  shall  see,  however,  that  this  belief  can  only 
receive  qualified  acceptance  in  the  light  of  the  latest  views  of  this 
branch  of  physiology.  A  decrease  in  the  supply  to  a  part  is  followed 
by  a  diminution  of  nutritive  material,  and,  as  a  consequence,  hyponu- 
trition  prevails.  This  distinction  at  once  divides  local  disturbances  of 
the  circulation  into  two  groups,  viz.,  hyperaemia,  a  condition  in  which 
there  is  an  excess  of  blood  in  a  part ;  and  anaemia,  a  condition  in  which 
there  is  a  deficiency  of  blood  in  a  part.  In  this  division,  however,  the 
latter  term  is  used  inaccurately,  for  anaemia  has  come  to  be  applied  to 
those  conditions  in  which  there  is  a  deficiency  of  red  corpuscles  in  the 
blood,  or  to  those  conditions  consequent  upon  hemorrhage,  in  which  the 
general  volume  of  the  blood  is  lessened  in  amount.  The  corresponding 
term,  indicating  an  excess  in  the  volume  of  the  circulatory  fluids,  is 
plethora.  The  word  ischaemia,  from  the  Greek  ischo,  I  stop,  is  used  to 
express  the  condition  opposite  to  that  of  hyperaemia. 

Condition  of  the  Blood. 

There  are  two  elements  which  enter  into  the  discussion  of  the  sub- 
ject of  the  relationship  existing  between  nutrition  and  circulation,  the 
first  being  the  composition  of  the  blood,  and,  secondly,  its  mode  of  dis- 
tribution— its  equable  supply  to  the  several  tissues  and  organs  of  the 
body.  The  first  is  a  factor  of  prime  importance,  irrespective  of  the 
second,  for  abnormalities  in  the  composition  of  the  blood,  the  vehicle 
for  nutritive  material,  and  of  Avhat  is  of  almost  equal  importance, 
the  waste-products  formed  in  the  body,  are  inevitable  precursors  of 
disturbances  of  the  normal  nutrition  of  tissues — /.  e.,  are  productive  of 
disease. 

The  first  essential  to  the  proper  functionating  of  the  great  chemical 

69 


70  DISTURBANCES  OF  THE  VASCULAR  SYSTEM. 

laboratory,  the  human  body,  is  that  it  shall  receive  material  which  will 
enable  it  to  continue  its  great  variety  of  chemical  operations.  The  first 
of  these  materials,  in  point  of  importance,  is  oxygen  ;  for,  as  pointed 
out  by  the  physiologist,  vital  action  is  largely  dependent  upon  the  pro- 
cess of  oxidation. 

In  the  absence  of  oxygen  the  protoplasm  of  cells,  no  matter  how 
diiferentiated,  whether  a  neuron  of  the  brain,  a  parenchymatous  cell  of 
the  liver,  an  epithelial  cell  of  the  kidney,  or  the  odontoblast  of  a  dental 
pulp,  cannot  be  the  seat  of  chemical  reactions  and  reductions  which 
transform  nutritive  matter  into  protoplasm,  or  which  reduce  the  waste- 
products  of  cellular  activity  to  substances  which  may  be  removed  from 
the  cell.  Oxygen,  therefore,  is  essential,  not  only  to  the  reconstructive 
action,  constructive  metamorphosis,  but  also  to  the  removal  of  waste- 
products,  which,  if  remaining  unoxidized,  literally  poison  the  protoplasm 
with  which  they  remain  in  contact. 

Changes  in  the  Composition  of  the  Blood. — The  first  factor  to  be 
studied,  therefore,  in  connection  with  the  composition  of  the  blood  is  its 
oxygen  capacity — in  short,  the  number  of  its  red  corpuscles.  It  is  usu- 
ally stated  that  the  average  number  of  red  corpuscles  in  human  blood  is 
5,000,000  in  a  cubic  millimetre.^  This  proportion  is  temporarily  altered 
by  divers  influences,  so  that  a  deficiency  of  red  corpuscles  is  only  spoken 
of  when  the  deficiency  is  persistent.  When  the  proportion  is  lessened 
the  condition  is  spoken  of  as  oligocythsemia  (Greek  oligos,  few).  The 
special  constituent  of  the  corpuscle  with  which  oxygen-carrying  is  asso- 
ciated is  haemoglobin,  chemically  an  albuminate  of  iron,  Avhich  holds 
oxygen  with  a  light  affinity  which  carbon  dioxid  overcomes,  and  displaces 
the  oxygen.  If  haemoglobin  be  deficient  in  amount,  or  if  there  be  such 
a  pulmonary  condition  that  a  free  interchange  between  the  blood  in  the 
capillaries  of  the  lungs  and  the  air  in  the  acini  is,  interfered  with,  it  is  evi- 
dent that  the  supply  of  oxygen  to  the  tissues  will  be  deficient,  and  a  con- 
dition of  suboxidation  will  exist  throughout  the  body,  nutrition  will  be 
imperfect,  and  waste-products  of  incomplete  metabolism  be  formed,  with 
a  tendency  to  their  retention.  Arterial  blood  containing  those  substances 
fitted  for  nutrition  becomes  unfitted  for  this  office  if  the  processes  of 
digestion,  absorption,  and  glandular  functions,  particularly  those  of  the 
liver,  do  not  properly  transform  food-stufiFs  into  substances  fitted  for  the 
proper  performance  of  cell-function.  Those  miniature  chemical  labora- 
tories, living-cells,  require  for  their  special  chemistry,  substances  elabo- 
rated by  the  great  laboratories  of  the  digestive  system.  If  these  sub- 
stances are  not  formed,  the  cells  throughout  the  body  receive  material 
unfit  for  their  purposes.  The  peculiar  chemistry  of  the  several  organs 
of  the  body  will  modifiy  the  substances  contained  in,  particularly,  the 
^  Foster's  Physiology,  5th  ed. 


COAGULATION  OF  THE  BLOOD.  71 

venous  blood  of  any  region,  so  tluit  the  composition  of  the  blood  varies 
according  to  the  organ  in  which  it  is  found.  In  general  terms,  arterial 
blood  contains  the  nutritive  materials  of  the  body,  and  the  veins  the 
waste-products  ;  to  this  rule,  however,  there  are  marked  exceptions  ;  for 
example,  the  blood  of  the  renal  artery  contains  waste-matters  (urea, 
etc.)  to  be  eliminated,  and  the  blood  in  the  hepatic  veins  contains  the 
food-substances  which  have  been  prepared  by  the  liver. 

If,  owing  to  continued  faulty  physiology,  the  quality  of  the  blood  be 
altered,  either  by  not  receiving  projierly  elaborated  food-materials  or  from 
the  jiresence  of  an  undue  amount  of  substances  which  should  be  removed 
as  waste-products,  the  nutrition  of  organs  suffers,  and  there  is  inaug- 
urated the  series  of  disturbances  described  in  Chajitcr  IV.  Circulating 
in  the  body  the  waste-products  of  tissue-metabolism,  if  present  in  undue 
amount,  act  as  irritating  or  paralyzing  agencies  upon  the  vital  activities 
of  cells,  particularly  upon  cells  whose  activities  are  below  normal,  hence 
they  are  productive  of  degenerations.  Urea  and  uric  acid  are  marked  ex- 
amples of  such  irritants.  If  the  elimination  of  urea  be  checked,  owing  to 
disease  of  the  kidneys,  the  soluble  urea  circulating  in  the  blood-current 
acts  as  a  poison  to  the  organs  of  the  body,  and  evidences  of  widespread  func- 
tional disturbance  make  their  appearance.  Uric  acid  in  the  form  of  solu- 
ble urates  of  sodium,  wliich  should  be  eliminated  by  the  kidneys,  if 
retained  in  undue  amount,  owing  to  kidney- disease,  is  precipitated  in 
regions  having  a  sluggish  circulation,  where  the  vitality  of  the  cells  has 
been  diminished  or  degenerations  are  in  progress.  It,  in  its  turn,  may 
act  as  an  irritant  in  parts  in  which  it  is  deposited. 

Substances  formed  in  the  intestinal  canal  as  the  result  of  faulty 
intestinal  digestion,  and  poisons  developed  there  through  the  action  of 
bacteria,  may  be  absorbed,  and  if  that  destroyer  of  poisons,  the  liver,^ 
fails  to  neutralize  them,  they  gain  entrance  to  the  general  circulation 
and  act  as  poisons  (see  Septicaemia  and  Pyaemia). 

Coagulation  op  the  Blood. 

The  blood  contains  a  substance,  probably  a  globulin,  out  of  which 
fibrin  is  formed  ;  hence  it  is  termed  fibrinogen.  It  is  permanently  solu- 
ble in  the  alkaline  blood-serum  under  normal  conditions  ;  but  when 
from  any  cause  injury  or  degeneration  of  white  blood-corpuscles  occurs, 
substances,  called  ferments,  are  set  free  from  the  corpuscles,  which 
in  the  presence  of  calcium  salts  (present  in  the  blood  as  phosphates 
and  carbonates)  combine  with  fibrinogen  to  form  a  new  compound, 
whose  solubility  is  altered,  and  a  new  and  solid  substance  makes  its 
appearance — fibrin.  This  reaction  occurs  in  blood  removed  from  the 
body,  constituting  what  is  called  the  coagulation  of  blood.  When 
'  Bruntoii,  Pharmacology  and  Therapeutics,  3d  ed. 


72 


DISTURBANCES  OF  THE  VASCULAR  SYSTEM. 


FiCx.  34. 


blood  is  drawn  in  a  vessel,  after  a  period  it  is  noted  that  it  changes 
from  a  fluid  to  a  jelly-like  mass,  red  in  color.  The  conditions  under 
which  the  blood  is  placed  cause  partial  disintegration  of  leucocytes, 
jiaraglobulin  and  ferments  are  set  free,  which,  combining  with  the 
fibrinogen  of  the  blood,  form  fibrin ;  the  corpuscular  elements  become 
entangled  in  the  meshes  of  the  fibrin.^  Under  some  conditions  this 
process  occurs  in  living  bloodvessels.  When  from  any  cause  the  endo- 
thelial cells  lining  bloodvessels  have  suffered  injury,  Avhether  by  me- 
chanical injury  or  the  presence  of  substances  which  cause  irritation, 
an  accumulation  of  leucocytes  occurs  in  the  locality  and  the  reaction 
called  coagulation  occurs.  The  process  seems  to  be  determined  by  a 
slowing  of  the  blood-current  in  the  affected  vessel,  and  it  is  extremely 
probable  that  changes  in  the  chemical  composition  of  the  blood  play  an 
important  part. 

Thrombus. — When  a  coagulum  forms  in  a  vessel  it  is  known  as  a 
thrombus  (Greek  thrombos,  a  clot  of  blood).  It  may  form  in  the  vessels 
or  in  the  heart ;  may  remain  where  it  has  formed,  or  be  transported 
to  other  parts,  forming  Avhat  is  called  an  embolus  (Greek  embolon,  a 
piston).  Whatever  its  situation,  the  significance  of  a  thrombus  or  embo- 
lus is  mechanical  interference  with  the  circu- 
lation, and  its  effects  are  governed  by  the 
extent  to  which  the  blood-supply  of  a  part  is 
occluded.  If  the  embolus  be  formed  of  tumor- 
cells  or  of  bacteria  which  have  gained  entrance 
'j^^^^^HS'^jr/y  to  the  circulation,  secondary  disease-processes 

"^^^^  '  are  set  up.      Remaining  in  the  situations  in 

which  they  were  formed,  thrombi  undergo  de- 
generative changes.  In  one  of  the  typical 
situations,  in  varicose  vessels,  when  the  vas- 
cular current  is  much  slowed,  thrombi  fre- 
quently form  and  undergo  calcareous  degen- 
eration (which  see),  forming  what  are  called 
phleboliths  (vein-stones).  If  the  occluded 
vessel  be  what  is  called  a  terminal  artery — 
that  is,  an  artery  Avhose  branches  spread  like 
those  of  a  tree,  without  anastomosis — the  area 
to  which  it  is  distributed  undergoes  degenera- 
tion and  death.  The  backward  pressure  from 
the  veins  upon  the  blood-current  of  the  capillaries  causes  rupture 
of  the  latter,  and  an  extravasation  of  blood  into  the  wedge-shaped 
(Fig.  34)  area  occurs,  forming,  what  is  called  a  hemorrhagic  infarct. 

^  For  extended  description   of   this   process   see  Foster's  Physiology  and   Landois' 
Physiology. 


Diagram  of  a  hemorrhagic  in- 
farct :  a,  artery  obliterated  by 
an  embolus  (e) ;  v,  vein  filled 
with  a  secondary  thrombus 
(th) ;  1,  centre  of  infarct,  which 
is  becoming  disintegrated;  2, 
area  of  extravasation ;  3,  area 
of  collateral  hypersemia.  (O. 
Weber.) 


PLATE   I. 


Fig.  1. 


Fig.   2. 


Severe  Asemia  with 
Leucoeytosis. 

Dry  preparation.  Fixed  with  picric  acid. 
Stained  with  hagmatoxylin  Bohmer,  x  300. 

Red  corpuscles  few,  almost  colorless,  varying 
in  size,  show  poikilocytosis ;  two  nucleated  reds 
(normoblasts).  The  increase  in  the  white  cells 
seen  to  be  in  the  polynuclear  elements.  (Rieder's 
"  Atlas  der  Klinischen  Mikroskopie  des  B lutes.") 


Splenic-myelogenic  Leuksenaia. 

Eosin-haematoxylin,  x  300.  Red  corpuscles 
rosy-red,  of  nearly  uniform  size,  round.  To  the 
left  a  normoblast  with  eccentrically  placed  nucleus. 
Many  large  mononuclear  leucocytes  (myelocytes) 
and  three  eosinophiles  seen.     (Rieder.) 


Fig.  3. 


Fig.   4. 


Splenic-myelogenic   Leukaemia. 

Same  case.  Eosin-hsematoxylin,  x  iioo.  One 
normoblast,  one  polynuclear  leucocyte,  one 
myelocyte,  two  eosinophiles.  The  neutrophilic 
granules  of  the  polynuclear  leucocyte  and  of  the 
myelocyte  do  not  show  with  this  stain.  The  large 
mononuclear  eosinophile  above  is  believed  to  be 
also  a  myelocyte  (Markzelle),  the  smaller  one  be- 
low, an  eosinophile  such  as  can  be  found  in  nor- 
mal blood.     (Rieder.) 


Myelocyte,   normoblast, 
inegaloblast. 

Triple  stain.  G,  Myelocyte  showing  neutro- 
philic granules  ;  H,  normoblast,  both  from  a  case 
of  splenic  myelogenic  leukaemia;  I,  large  nu- 
cleated red  corpucle  (megaloblast)  from  a  case  of 
pernicious  anaemia.     (Osier.) 


PHAGOCYTES  OF  THE  BLOOD. 


73 


The   death   of  the   dental    pulp   is   no  doubt   frequently  due  to  this 
process. 

Thrombi  formed  in  veins  may  find  their  way,  via  larger  veins  (Fig. 
35),  into  the  heart,  and  thence  be  driven  into  the  branches  of  the  pul- 

FrG.  35. 


A  thrombus  in  the  saphenous  vein,  showing 
the  projection  of  the  conical  end  of  the 
thrombus  into  the  femoral  vessel:  .S, 
saphenous  vein ;  T,  thrombus ;  C,  conical 
end  projecting  into  femoral  vein.  At  v,  v, 
opposite  the  valves,  the  thrombus  is  soft- 
ened.   (Virchow.) 


Embolus  impacted  at  the  bifurcation  of 
a  branch  of  the  pulmonary  artery, 
showing  the  formation  of  thrombi  be- 
hind and  in  front  of  it,  and  the  exten- 
sion of  these  as  far  as  the  entrance  of 
the  next  collateral  vessels :  E,  embo- 
lus; t,  V ,  secondary  thrombi.  (Virchow.) 


monary  artery.  Thrombi  formed  upon  the  arterial  side,  if  detached, 
are  driven  along  the  artery  to  a  vessel  or  junction  of  vessels  refusing 
passage  to  them,  when  the  results  of  thrombus  are  suddenly  set  up 
(Fig.  36). 

Phagocytes  of  the  Blood. 

The  white  corpuscles,  the  leucocytes  of  the  blood,  are  of  great 
clinical  importance.  Several  varieties  of  the  white  corpuscles  are 
to  be  recognized:^  1.  Lymphocytes,  derived  from  the  lymphoid  tis- 
sues of  the  body,  forming  20  to  30  per  cent,  of  all  of  the  leucocytes 
of  the  blood ;  they  are  probably  immature  leucocytes.  2.  Large 
leucocytes  having  a  single  nucleus,  which  take  up  acid  eosin,  .stain 
readily  (eosinophile.s),  forming  2  to  3  per  cent,  of  leucocytes  of  blood. 
3.  Smaller  leucocytes  containing  several  nuclei,  which  stain  only  with 
a  mixture  of  basic  and  acid  dyes,  and  hence  called  neuti'ophiles  ; 
they  form  two-thirds  the  entire  number  of  leucocytes.  4.  Transi- 
tional forms,  constituting  about  3  per  cent. ;  they  are  between  the 
mononuclear  and  polynuclear  forms.  5.  Eosinophile  cells,  size  of  Xo. 
3  nuclei,  variable  ;  they  constitute  from  2  to  4  per  cent,  of  leucocytes. 
(Plate  I.) 

Under  some  conditions,  notably  during  diseases  in  which  suppura- 
'  Park'.s  Surgery,  vol.  i.,  and  Metchnikoff's  Lectures. 


74 


DISTURBANCES  OF  THE   VASCULAR  SYSTEM. 


tion  occurs,  there  is  a  marked  increase  in  the  poly  nucleated  leucocytes. 
This  fact  has  been  applied  as  a  diagnostic  sign  of  the  existence  of  sup- 
puration ; '  if  leucocytosis  be  present  during  the  course  of  surgical  dis- 
eases, suppuration  and  retention  of  pus  are  to  be  suspected.  The  large 
mononuclear  and  the  polynuclear  forms  of  leucocytes  have  pronounced 
phagocytic  activity ;  it  is  held  that  the  reason  for  their  increase  is  the 
presence  in  some  part  of  the  body  of  substances  acting  as  tissue-irri- 
tants. These  cells  are  most  active  in  disposing  of  invading  bacteria^ 
and  are  present  in  great  numbers  in  areas  of  inflammation. 

Disturbances  of  the  Vascular  Mechanism. 

As  stated,  disturbances  in  the  equilibrium  of  the  circulation  may  be 
conveniently  grouped  under  two  heads,  a  hypo-  and  a  hyper-  group,  or 
conditions  of  ischsemia  and  conditions  of  hypersemia.  These  may  be 
again  divided  according  to  the  extent  of  the  disturbance,  ranging,  on 
the  one  hand,  from  a  slight  decrease  in  the  circulation  of  a  part,  to  its 
entire  occlusion  or  stoppage,  on  the  other  hand  :  the  range  extends 
from  a  slight  increase  of  circulation  to  an  entire  paralysis  of  vessel- 
walls.  In  either  event  the  tissues  depending  upon  the  supply  of  blood 
through  the  affected  vessels  are  adversely  affected,  it  may  be  to  the 
extent  of  their  death. 

The  grades  and  effects  of  both  types  of  vascular  disturbances  are 
graphically  represented  in  Fig.  37. 


Fig.  37. 
Health 

stimulation          / 

\                Atony 

Increased  Function  j 
Hyperaemia     1 

\  Lessened  Function 

\                 t 

\      Ischaemia           §' 

Hyperplasia     1 
Inflammation  \ 

\      Atrophy             2 
\                                ^ 

\                               ^ 

I       Occlusion 

Defeneration 
Stagnation 

Necrosis 

Necrosis 

Degeneration 
Stagnation 

Death 


The  cause  of  the  lessened  blood-supply  to  an  organ  may  be  at  any 
portion  of  the  circulatory  apparatus — the  heart,  the  arteries,  capillaries, 
or  veins.  The  heart  itself,  through  degenerative  changes  in  its  muscle,  as 
in  fatty  degeneration  of  the  organ,  may  propel  the  blood  with  insufficient 

^  Cabot,  Boston  Med.  and  Surg.  Journ.,  March  22,  1894. 


DISTURBANCES  OF  THE   VASCULAR  MECHANISM.  75 

force.  The  presence  of  effusions  in  the  pericardium  may  lessen  the 
force  of  the  heart's  contraction.  If  an  obstruction  (hie  to  disease  of  the 
valves  of  the  heart  causes  a  narrowing  of  any  of  the  orifices  of  the 
heart,  the  blood-pressure  in  the  arteries  falls,  hence  circulation  is  less 
active.  If,  as  the  consequence  of  disease  of  the  valves  of  the  heart, 
these  structures  do  not  entirely  close  their  respective  orifices,  there  is  a 
backward  flow  of  blood  into  the  corresponding  heart-cavity  and  tlie 
pressure  in  the  vessels  is  lessened.  Owing  to  degenerations  of  the  walls 
of  the  vessels,  mainly  the  arteries,  they  may  lose  their  elasticity,  and 
hence  this  element  of  equalizing  blood-pressure  fails  and  local  circula- 
tion becomes  disordered.  The  presence  of  a  thrombus  or  embolus  may 
mechanically  impede  the  flow  of  blood  to  or  from  a  part. 

In  any  of  these  cases  the  tissues  of  the  body  suffer  a  disturbance  of 
their  blood-supply  and  are  in  danger  of  the  hyponutritional  changes 
described  in  Chapter  IV.  These  changes  in  the  vascular  mechanism 
frequently  occur  at  a  time  of  life  when  the  vitality  of  tissues  is  on  the 
wane,  so  that  degenerative  changes  are  common.  The  changes  in  the 
vessels  may  be  localized,  in  which  case  the  nutritional  effects  are  in 
correspondence. 

Hypersemia. — The  term  hypersemia  has  reference  to  a  localized  con- 
dition. It  means  an  increase  in  the  activity  of  the  circulation  of  a  part. 
There  are,  however,  conditions  in  which  the  entire  vascular  system  ap- 
pears to  be  overfull ;  the  patient  is  said  to  be  plethoric.  Individuals  who 
present  this  appearance  are  of  two  classes  :  those  in  which  the  vessels 
appear  to  be  overfull  and  the  circulation  very  active,  or  sthenic  plethora, 
and  those  in  which  overfulness  of  vessels  is  associated  with  a  sluggish 
circulation,  or  asthenic  plethora.  In  sthenic  plethora  the  general  vital 
processes  are  active,  and  inflammations  are  quickly  lighted  up  and  run 
an  active,  but  not  dangerous  course  ;  the  condition  exhibits  the  phenom- 
ena of  overfull  arteries.  On  the  contrary,  in  asthenic  plethora,  while 
the  vessels  are  overfull,  the  circulation  is  sluggish  and  vital  processes 
appear  to  be  in  correspondence.  It  is  these  two  types  which  probably 
gave  origin  to  the  names  of  two  of  the  basal  temperaments,  the  san- 
guineous and  lymphatic.  Both  conditions  certainly  exercise  a  govern- 
ing influence  in  pathogenesis  in  the  classes  of  clinical  histories,  prog- 
nosis, and  treatment  of  diseases  to  which  such  persons  fall  victims. 

The  Pulse. — These  and  other  conditions  of  the  circulatory  apparatus, 
are  noted  by  studying  the  pulse — i  e.,  the  force,  frequency,  and  regularity 
with  which  the  blood  is  driven  through  the  vessels.  A  knowledge  of  the 
general  condition  of  the  circulatory  apparatus  is  gained  by  noting,  first, 
the  condition  of  the  heart-beat.  In  a  normal  condition  of  the  circula- 
tory apparatus  the  heart-pulsations  number  from  70  to  80  a  minute, 
accompanied  by  two  distinct  sounds  with  an  interval  between  them,  and 


76  DISTURBANCES  OF  THE   VASCULAR  SYSTEM. 

the  sensation,  Avhen  a  superficial  artery  is  pressed  upon,  of  a  quickly 
rising  and  quickly  subsiding  wave  and  with  a  moderate  degree  of  ten- 
sion, the  artery  filling  like  an  elastic  tube.  Any  variation  in  any  of 
these  particulars  indicates  necessarily  a  disturbance  in  the  vascular  mech- 
anism. If  the  heart-sound  is  feeble,  it  indicates  lack  of  power,  the 
pulse-wave,  on  measurement  with  a  sphygmograph,  showdng  a  short 
wave.  If  the  contraction  be  slow,  below  70,  it  is  noted  in  the  pulse ;  if 
both  slow  and  weak,  the  pulse  lacks  tension,  is  compressible.  If  in- 
stead of  tlie  normal  heart-sound  a  murmur  or  murmurs  are  heard,  dis- 
turbance of  the  valves  of  the  heart  is  indicated,  and  the  tension  of  the 
arteries  is  below  normal,  the  pulse-w^ave  is  disordered.  In  case  of  nar- 
rowing of  the  entrance  of  the  aorta  (aortic  stenosis)  the  wave  rises 
quickly  and  falls  suddenly.  In  case  the  mitral  valve  fails  to  completely 
separate  the  auricle  and  ventricle  in  contraction,  the  wave  is  small  and 
irregular.  If  the  heart-sounds  are  pronounced,  it  indicates  that  a  full 
volume  of  blood  is  being  driven  into  the  aorta. 

Turning  from  an  examination  of  the  heart  to  a  study  of  the  arteries 
themselves,  valuable  indications  as  to  the  condition  of  the  circulation 
are  obtainable.  It  is  to  be  recalled  that  the  arteries  are  kept  in  a  state 
of  moderate  contraction  through  the  influence  of  the  vasomotor  nerves, 
probably  by  a  balance  between  the  influence  of  vasoconstrictor  and  vaso- 
dilator nerves.  This  point  is,  however,  not  well  made  out ;  it  is  not 
clearly  determined  whether  dilatation  occurs  as  the  result  of  stimulation 
of  one  class  of  nerves,  and  contraction  to  stimulation  of  another  class,  or 
Avhether  contraction  is  due  to  a  set  of  nerves  which,  when  dilatation  oc- 
curs, are  inactive.  The  latter  hypothesis  would  imply  that  when  vaso- 
motor paralvsis  occurs  the  A'essels  are  passively  dilated  to  more  than 
their  normal  size  and  are  inelastic,  this  agreeing  with  observed  clinical 
phenomena.  The  arteries  are  normally  in  a  state  of  tension,  so  that 
when  the  blood-column  contained  in  them  is  pressed  upon  by  a  mass  of 
blood  ejected  from  the  left  ventricle  the  column  is  impelled  forw^ard, 
which,  meeting  the  resistance  of  the  blood  in  the  smaller  vessels  beyond 
the  arterial  trunk,  causes  an  elastic  distention  of  the  artery. 

The  tension  of  the  artery  may  be  raised  or  lowered,  according  as  the 
vessel  is  in  more  than  normal  or  less  than  normal  contraction.  When 
the  artery  is  in  extreme  contraction  owing  to  overstimulation  of  the 
vasoconstrictor  nerves,  or  from  irritation  of  the  vasomotor  centre,  the 
pulse  is  found  to  be  small  and  hard  ;  hard  because  of  the  tenseness  of 
the  arterial  wall,  and  small  for  the  same  reason — the  blood-column  is 
unable  to  dilate  the  tense  vessels.^  This  is  the  condition  found  in  angina 
pectoris  (neuralgia  of  the  heart),  in  which  the  heart  labors  to  overcome 
the  spasmodic  contraction  and  may  suffer  paralysis  in  its  efforts.     The 

'  Hare,  Practical  Diagnosu,  1896. 


ARTERIAL  HYPEREMIA.  77 

administration  of  the  nitrites,  amyl  nitrite  or  trinitrin,  paralyzes  the 
nerve-centre,  dilatation  of  the  vessels  occurs,  and  the  heart  is  relieved/ 
Changes  in  the  arterial  wall  due  to  disease  of  the  coats  may  bring  about 
a  condition  of  heightened  tension. 

The  conditions  of  the  pulse  are  referred  to  as  frequent  or  infrequent, 
corresponding  with  the  heart-beat ;  as  regular  or  irregular,  corresponding 
with  the  heart-beat.  The  pulse  may  be  full  or  small ;  full,  relating  to 
the  volume  and  the  extent  of  arterial  expansion.  Fulness  is  usuallv 
associated  with  strength  of  pulse,  although  not  always.  A  small  pulse 
is  usually  a  weak  pulse ;  but  if  the  artery  be  much  contracted,  it  may 
be  both  small  and  strong.  The  pulse  may  be  soft  or  hard ;  hard  in 
increased  tension  (see  above) ;  soft  with  diminished  tension  and  dimin- 
ished heart-power.^  A  hard,  full,  frequent  pulse  occurs  in  active  in- 
flammations. A  hard  pulse,  full  or  small,  bounding  or  not,  if  uncon- 
nected with  acute  symptoms,  leads  to  suspicion  of  cardiac  disease  or 
an  affection  of  the  artery  itself,  A  very  frequent  pulse,  but  feeble  and 
compressible,  is  the  pulse  of  marked  debility,  of  prostration,  of  collapse. 

It  is  by  these  several  signs  that  the  mode  of  distribution  of  blood 
throughout  the  body  is  gauged,  although  not  positively  determined,  for 
disturbances  in  the  circulation  of  a  part  may  occur,  and  only  be  deter- 
mined by  a  symptomatology  referable  to  the  part. 

In  the  beginning  of  this  chapter  it  was  stated  that  there  are  two 
recognized  types  of  hypereemia  :  one  in  which  the  distention  of  vessels 
was  upon  the  arterial,  the  other  in  which  it  is  upon  the  venous  side  of 
the  circulation.  The  two  types  differ  as  to  causes,  phenomena,  and 
effects,  and  as  to  the  indicated  treatment  for  each. 

Arterial  Hyperemia. 

Arterial  or  active  hypersemia  is  an  increase  in  the  amount  of  blood 
in  the  dilated  arteries  of  a  ])art. 

Causes. — The  direct  cause  of  hypersemia  of  a  part  is  a  lessened  arte- 
rial resistance  ;  the  tension  of  the  arterial  walls  is  lessened  by  a  stimula- 
tion of  the  vasodilator  nerves  or  by  a  sedation  of  the  vasoconstrictor 
nerves,  the  former  being  the  more  probable  explanation.  It  expresses  the 
reaction  which  occurs  as  the  consequence  of  the  presence  of  an  irritant. 
Alternate  rise  and  fall  in  arterial  tension  occur  in  health  ;  it  is  only 
when  the  condition  is  prolonged  that  it  becomes  pathological.  If  the 
sensory  nerves  of  a  part  are  stimulated  or  irritated,  hypersemia  of  the 
irritated  parts  occurs  as  a  reflex.  If  the  surface  of  the  body  be  irritated 
at  certain  points,  as  by  the  application  of  heat,  it  appears  that  in  some 
cases  hypersemia  may  be  induced  in  deeper-seated  organs  as  a  reflex.* 

'  Brunton's  Pharmacology.  -  DaC'osta,  Medical  Diagnosis. 

^  Green's  Pathology  and  Morbid  Anatomy. 


78  DISTURBANCES  OF  THE  VASCULAR  SYSTEM. 

Hypersemia  may  be  compensatoiy,  as  when,  through  the  removal  of  one 
of  a  pair  of  organs  having  the  same  function,  an  increased  blood-supply 
is  present,  and  increased  M'ork  is  performed  by  the  remaining  organ. 

Symptoms. — The  symptoms  accompanying  hypersemia  of  a  part  are 
such  as  would  be  directly  surmised  as  soon  as  the  condition  was  defined. 
There  are  increased  redness,  an  elevation  of  temperature,  and  more  or 
less  throbbing,  and  in  some  cases  some  degree  of  throbbing  pain.^ 

Patholog-y. — The  arteries  are  dilated  :  there  is  an  increased  flow  of 
blood  through  them  and  also  to  them  through  their  own  nutritive 
arteries  ;  the  pressure  in  the  veins  rises,  but  exudation  does  not  appear 
to  increase  in  all  cases,  as  there  is  no  increase  of  lymph-pressure,  although 
in  marked  cases  cedema  may  occur.  Two  types  of  arterial  hyperseraia 
appear  to  exist :  one  due  to  excitation  of  the  vasodilator  fibres,  a  neuro- 
tonic congestion ;  the  other,  a  neuroparalytic  congestion,  caused  by 
paralysis  or  sedation  of  the  vasoconstrictor  fibres  (Recklinghausen). 

Results  of  Active  Hypereemia. — The  nutrition  of  the  part  is  in- 
creased ;  there  is  in  the  less  pronounced  cases  an  increase  in  the  func- 
tional activity  of  the  part ;  secretion  is  increased ;  the  vital  activities 
are  elevated.  In  more  pronounced  cases,  where  the  symptoms  of  red- 
ness, heat,  swelling,  and  throbbing  pain  occur,  the  function  of  the  part 
is  disturbed.  Many  of  the  cases  formerly  included  among  the  mild 
inflammations  are  now  placed  under  the  head  of  active  hypersemia. 

The  character  and  composition  of  the  exudates  differ  widely  in  the 
two  conditions  : 

Hijperdemic  Exudates.  Inflammatory  Exudates. 

Poor  in  albumin.  Rich  in  albumin. 

Rarely  coagulate  in  tissue.  Usually  coagulate  in  tissue. 

Contain  few  cells.  Contain  numerous  cells. 

Low  specific  gravity.  High  specific  gravity. 

Contain  no  peptone.  Contain  peptone.^ 

The  lesser  forms  of  hypersemia  if  continued  may  lead  to  hypertrophy 
of  the  affected  organ  and  of  the  vessels.  In  the  more  marked  forms  the 
changes  induced  approach  the  degenerations. 

Treatment. — The  principle  of  treatment  is  to  remove  the  cause  and 
procure  surgical  rest.  The  source  of  the  irritation  is  to  be  sought  out 
and  removed  when  possible ;  as  a  rule,  the  symptoms  then  promptly 
subside.  It  may  be  that  the  conditions  existing  require  treatment  irre- 
spective of  the  cause,  which  may  not  be  determined  or  be  absent,  the 
vessels  being  dilated  as  the  effect  of  a  previously  acting  cause.  The 
principle  of  treatment  is  the  reduction  of  the  dilated  vessels.  This  is 
attempted  at  times  through  the  use  of  drugs ;  for  example,  the  adminis- 

^  Warren,  Surgical  Pathology  and  Therapeutics.  ^  Park's  Surgery,  vol.  i.,  p.  25. 


VENOUS  HYPEBJEMIA.  79 

tration  of  ergot,  which,  by  stimuhiting  the  vasoconstrictor  system,  les- 
sens the  calibre  of  the  dilated  vessels.  The  antagonist  of  ergot,  aconite, 
has  also  been  used.  By  paralyzing  the  vasoconstrictor  system  and  ([niet- 
ing  the  usually  overacting  heart-muscle  it  lessens  the  amount  of  blood 
flowing  to  a  part  in  a  given  time. 

The  usual  method  of  inducing  contraction  is  by  local  applications  of 
dry  cold,  which  cause  contraction  of  the  arteries. 

The  principle  of  derivation  is  also  employed  :  by  local  bloodletting, 
by  incision,  wet  cups,  or  leeches  applied  beyond  the  margins  of  the 
hypersemic  area,  the  engorged  vessels  are  unloaded.  Frequently  the 
administration  of  a  diaphoretic  or  diuretic,  by  diverting  the  blood-cur- 
rent, causes  a  lessened  flow  to  the  affected  area.  The  administration  of 
a  saline  cathartic  lessens  the  fluid  volume  of  the  blood,  and,  conjoined 
with  local  measures,  reduces  the  engorged  vessels. 

What  is  known  as  counterirritation  is  a  common  means  of  treatment. 
An  irritant,  such  as  a  mustard-plaster  or  a  blister,  applied  at  a  distance 
from  the  affected  part,  induces  a  flow  of  blood  to  the  point  of  applica- 
tion and  lessens  the  amount  of  blood  in  other  parts.  The  volume  of 
the  blood  being  in  definite  amount,  if  an  excess  exist  in  any  part,  a 
deficiency  will  be  found  in  other  parts. 

Sedative  astringents  (the  liquor  plumbi  subacetatis)  are  used  to  con- 
tract dilated  vessels.  Other  astringents  (see  Pharmacology)  induce  dila- 
tation of  vessels,  and  so  are  contraindicated. 

Perhaps  the  most  effective  measure  is  local  bloodletting,  and  in  the 
more  continued  cases  the  repeated  application  of  cold. 

Venous  Hyperemia. 

By  venous  hyperemia  is  meant  an  excess  of  blood  in  the  dilated 
veins  of  a  part. 

Causes. — Its  causes  are  mechanical  interference  with  the  return  of 
the  blood  to  the  heart. 

Symptoms. — The  symptoms  of  this  condition  are  blueness  (instead 
of  redness),  a  lessened  temperature,  and  swelling. 

Pathology  and  Morbid  Anatomy. — The  veins  are  dilated,  the  cur- 
rent is  slowed,  and  intravenous  pressure  is  increased,  in  consequence  of 
which  watery  exudations  occur  in  the  parts  about  them.  The  deficiency 
of  arterial  and  the  excess  of  venous  blood,  with  interference  with  its 
return  to  the  heart,  are  followed  by  deficient  supply  of  oxygen,  a  lessened 
food-su])ply,  and  the  retention  of  waste-products  :  the  effects  are  in 
oorrespondence,  vital  processes  are  lessened,  secretion  is  diminished, 
there  is  less  oxidation,  and  hence  less  heat  is  produced  and  less  work 
is  done.  The  functional  activity  of  the  parts  suffers,  and  degenerations, 
atrophy,  or  necrosis  may  occur. 


80  DISTURBANCES  OF  THE   VASCULAR  SYSTEM. 

Treatment. — The  principle  of  treatment  is  the  removal  of  the  me- 
chanical obstruction  to  the  return  of  the  blood  and  mechanical  sup- 
port of  the  engorged  vessels.  This  latter  is  accomplished  by  means 
of  elastic  bandages,  and  in  situations  in  which  these  cannot  be  used, 
astringents  may  be  employed.  The  part  is  elevated  when  possible,  to 
aid  in  the  return  of  the  blood  to  the  heart. 

The  succeeding  type  of  tissue  and  vascular  reaction  toward  an  irri- 
tant— inflammation — must  be  treated  as  a  process  sui  generis,  although 
exhibiting  many  features  of  pronounced  arterial  hypersemia. 

Inflammation. 

There  is  no  condition  described  in  pathology  which  has  received  such 
a  variety  of  definitions  as  that  of  inflammation.  A  general  consensus 
of  opinion  places  inflammation  in  the  category  of  the  conservative  pro- 
cesses, viewing  it  as  essentially  Nature's  means  of  ridding  the  tissues 
of  an  intruding  substance — an  irritant. 

As  a  general  description,  there  is  perhaps  no  better  definition 
than  that  of  Sanderson  :  ^  "  Inflammation  is  the  succession  of  changes 
which  occurs  in  a  living  tissue  as  the  result  of  some  kind  of  injury, 
provided  that  this  injury  be  insufficient  to  immediately  destroy  its 
vitality." 

A  definition  which  expresses  the  pathological  features  found  in  this 
condition  better  than  any  other  is  that  of  Ziegler : ^  "It  is  essen- 
tially a  local  tissue-degeneration  combined  with  pathological  exudations 
from  the  bloodvessels,  followed  sooner  or  later  by  tissue-proliferation, 
leading  to  regeneration  or  hypertrophy." 

It  has  been  suggested^  that  the  term  inflammation  be  dropped  from 
use,  as  it  includes  so  many  factors  which  are  variable  in  occurrence  as 
to  give  the  word  but  indefinite  meaning. 

Causes. — The  causes  are  injuries  of  any  description  which  induce  a 
higher  degree  of  irritation  than  those  producing  active  hypersemia.  The 
sources  of  these  irritations  or  injury  are  many  and  varied.  They  may 
be  included  under  the  heads  of  mechanical  violence,  the  action  of 
physical  forces,  the  action  of  chemical  substances,  and  the  action  of 
parasites  and  their  products.  Any  one  or  more  of  these  influences 
acting  upon  a  vital  part  may  induce  the  inflammatory  process. 

The  causes  may  be  extrinsic  or  intrinsic ;  while  most  of  them  act 
from  the  exterior  of  the  body,  substances  formed  in  the  body,  such 
as  uric  acid,  are  sufficient  irritants  at  times. 

Inflammations  which  are  caused  by  the  action  of  physical  or  chemi- 
cal agencies  are  usually  termed  simple ;  those  arising  through  the  in- 

^  Holmes'  Systera  of  Surgery,  vol.  i.  ^  General  Pathology,  1895. 

^  Thoma,  General  Pathology,  vol.  i. 


INFLA  M3IA  TION. 


81 


fliience  of  vegetable  parasites  or  their  products  are  named  infective  in- 
flammations. 

Pathology. — Inflammation  may  be  fitly  regarded  as  one  stage  of  a 
series  of  nutritive  disorders  which  begins  in  stimulation  and  ends  in 
necrosis.  It  is  a  profound  disturbance  of  the  nutritive  functions  of  a 
part.  The  pathology  of  inflammation  is  studied  by  inducing  the  condi- 
tion in  transparent  and  vascular  membranes  of  animals,  which  may  be 
fixed  to  the  stage  of  the  microscope. 

The  first  effect  of  the  application  of  a  sufficient  irritant  to  a  part  is 
the  quick  contraction  of  the  arteries,  followed  immediately  by  a  dilata- 
tion of  arteries  and  veins,  the  velocity  of  the  current  increasing ;  the 
blood-pressure  is  at  this  stage  apparently  not  marked,  for  there  is  but 

Fig.  38. 


Inflamed  human  omentum.  The  phenomena  of  inflammation  are  seen  in  the  veins  and  capil- 
laries, the  condition  being  normal  at  the  artery  (c),  where  b  represents  endothelium  covering 
the  trabecula  (a).  In  the  vein  id)  there  are  many  white  corpuscles  along  the  wall :  some  of 
these  are  emigrating  (e) ;/,  desquamated  endothelium ;  g,  extravasated  red  corpuscles.  (Ziegler.) 

little  dilatation  of  the  capillaries.  Up  to  this  point  there  is  nothing  ob- 
served which  could  not  be  explained  by  a  paralysis  of  the  vasoconstrictor 
or  stimulation  of  the  vasodilator  nerves  ;  the  process  of  inflammation 
proper  begins  when  the  blood-stream  in  the  emergent  veins  is  seen  to 
be  retarded  and  an  exudation  is  poured  out  of  the  small  veins  and  cap- 
illaries;  with  the  slowing  of  the  current  the  increased  blood-pressure 
causes  a  marked  dilatation  of  the  capillaries.  An  evident  change  may 
now  be  noted  in  the  condition  of  the  walls  of  the  vessels.^     The  leuco- 

^  Cohnheim  and  Samuel. 


82  DISTURBANCES  OF  THE  VASCULAR  SYSTEM. 

cytes,  which  before  the  inception  of  the  condition  were  few  and  scattered, 
are  seen  from  the  beginning  of  this  process  of  retardation  to  cling  and 
mass  in  numbers  along  the  walls  of  the  smallest  veins,  the  large  mononu- 
clear and  the  multinuclear  forms  particularly.  Instead  of  the  usual  exu- 
date of  lymph,  the  vessels  of  the  area  now  pour  out  an  abundant  exudate 
rich  in  albumin,  and  soon  the  white  corpuscles  may  be  seen  making  their 
way  through  stomata  of  the  veins  to  the  intercellular  spaces  (Fig.  38). 
The  area  about  the  bloodvessels  is  soon  filled  with  a  mass  of  mobile 
cells.  The  origin  of  all  these  cells  is  a  mooted  point.  It  was  taught 
by  Virchow  that  they  arose  from  the  multiplication  of  the  connec- 
tive-tissue corpuscles  of  the  part ;  and  later,  their  origin  was  stated  by 
Cohnheim  to  be  solely  from  the  leucocytes  which  had  made  their  escape 
from  the  vessels.  It  is  the  belief  at  present  that  they  arise  mainly  from 
the  leucocytes  at  this  stage  of  the  inflammatory  process. 

The  diapedesis  is  explained  by  Metchnikoffas  Nature's  defence  against 
an  intruding  and  injurious  body.  When  such  a  body,  or  when  a  source 
of  marked  irritation  is  present,  the  leucocytes  throng  to  the  point  of 
irritation,  emerge  from  the  vessels,  and  attack  the  intruder,  exercising 
their  phagocytic  activity  against  it.  If  the  intruder  is  of  smaller  size 
than  the  leucocytes  (as  bacteria),  it  is  enclosed  by  the  latter,  killed,  and 
digested.  Large  bodies  are  attacked  and  surrounded  en  masse  by  leuco- 
cytes. If  the  phagocytic  cells  conquer,  the  acute  symptoms  subside  and 
a  series  of  changes  occur  which  lead  to  a  restoration  of  health.  If  the 
bacteria  or  other  intruders  prevail,  the  phagocytes  succumb,  die,  and 
form  what  are  called  pus-corpuscles. 

The  blood  in  the  capillaries  comes  to  a  standstill,  a  condition  of 
stasis.  Coagulation  of  the  blood,  however,  does  not  occur,  as  a  rule  ;  for 
if  the  blood-flow  be  re-established,  the  separate  red  corpuscles  are  seen, 
one  by  one,  to  roll  away  from  the  genera!  mass  until  all  are  in  move- 
ment and  stasis  ceases  (Thoma).  The  affected  area  becomes  filled  with  a 
mass  of  indifferent  cells  and  remnants  of  broken-down  tissue,  for  it  ap- 
pears that  the  nutritive  balance  of  the  tissue-elements  of  the  part  is 
entirely  lost,  and  that  profound  degenerative  changes  occur  in  them  ;  it 
is  believed,  therefore,  that  the  source  of  the  cells  at  the  height  of  the 
inflammatory  process  is  from  the  leucocytes  alone.  The  albuminous 
exudate,  in  the  presence  of  injured  leucocytes,  is  in  fit  condition  to 
coagulate,  and  coagulation  of  the  effusions  occurs.  The  area  of  inflam- 
mation now  represents  virtually  a  mass  of  embryonic  tissue  containing 
foreign  substances.  The  inflammation  may  take  one  of  two  courses  : 
the  inflammation  may  abate,  and  a  restoration  of  health  and  regenera- 
tion of  tissue  in  the  parts  take  place  ;  or  the  cells  of  the  exudation, 
together  with  more  or  less  of  the  tissue,  may  die.  In  the  former  case 
the  process  is  called  resolution  ;  in  the  latter,  suppuration. 


INFLA  MM  A  TION.  83 

It  is  interesting,  in  this  connection,  to  review  the  beliefs  as  to  the 
causative  agents  in  inflaniniation.  It  has  been  demonstrated  quite 
clearly  that  the  process  of  suppuration  occurs  only  in  the  presence  of 
bacteria  or  their  waste-products.  It  is  held  by  one  school  of  pathologists 
that  true  infiamnuition  also  occurs  only  in  consequence  of  the  presence 
of  similar  causes,  the  inference  being  drawn  mainly  from  Metchnikoff's 
observations.  Another  school  hold  that  inflammations  are  of  two  types 
— simple  and  infective.  If  suppuration  occurs  only  in  the  presence 
of  bacteria  or  their  products,  then  pus-formation  cannot  be  a  result  of 
what  are  termed  simple  inflammations.  We  are  compelled,  therefore, 
either  to  believe  that  the  evidence  as  to  the  invariable  association  of  pus 
and  bacteria  is  insufticient  and  faulty,  or  else  hold  that  all  inflammations 
are  bacterial.  The  evidence  as  it  exists  divides  inflammations  into  two 
classes  :  first,  those  certainly  infective ;  secondly,  those  not  certainly 
infective. 

Symptoms. — The  classical  symptoms  of  inflammation  are  rubor, 
tumor,  dolor,  color,  effunctio  laesa,  or  redness,  swelling,  pain,  heat,  with 
disturbance  of  function.  The  general  symptoms  are  usually  an  increased 
heart-action,  some  elevation  of  the  temperature  of  the  body,  and  dis- 
turbances in  secretions.  The  redness  is  due  to  an  increased  amount  of 
blood  in  the  part,  the  color  being  deeper  in  the  centre  of  the  inflamma- 
tory area.  The  swelling  is  due  to  the  exudation  ;  the  hardness  of  the 
swelling  being  due  to  coagulation  of  the  effusion.  The  pain  is  the  result 
of  the  pressure  of  the  effusion  upon  sensory  nerve-terminals  ;  it  is  fre- 
quently throbbing,  in  correspondence  with  the  heart-beat.  The  heat  is 
owing  to  the  greater  amount  of  arterial  blood  carried  to  the  part ;  experi- 
ments to  show  that  there  is  an  increased  generation  of  heat  in  an  inflamed 
part  have  resulted  negatively.^  The  function  of  the  part  is  disturbed  from 
mechanical  and  vital  reasons ;  the  presence  of  the  exudation  itself  tends 
to  disturb  functional  activity,  but  there  is,  beyond  doubt,  in  inflam- 
mation a  profound  disturbance  of  the  nutritive  balance  in  the  tissues. 
Any  one  or  more  of  these  symptoms,  except  disturbance  of  function, 
which  is  a  truly  cardinal  symptom,  may  be  absent  in  some  anatomical 
situations. 

Seat  of  Inflammation. — Virchow  divided  inflammations  into  par- 
enchymatous and  interstitial,  according  to  the  portion  of  the  organ 
attacked.  Parenchymatous,  those  in  which  the  functional  cells  of  a  part 
were  affected  ;  interstitial,  those  in  which  the  connective  tissue  was 
affected.  True  inflammation  occurs  only  in  the  perivascular  connective 
tissue,  so  that  it  is  always  interstitial.  It  has  been  suggested  that  the 
term  parenchymatous  inflammation  be  abandoned,  but  there  is  no  other 
term  at  present  which  expresses  the  condition — a  profound  disturbance 
^  Warren's  Surgical  Pathology  and  Therapeutics,  1895. 


84 


DISTURBANCES  OF  THE   VASCULAR  SYSTEM. 


of  the  vascular  supply  underlying  these  cells,  accompanied  by  a  granular 
degeneration  of  the  cells  and  their  death. 

When  the  effusion  contains  a  small  amount  of  albumin  and  cor- 
puscles the  condition  is  called  a  serous  inflammation. 

In  eflusions  largely  corpuscular  coagulation  occurs,  and  a  fibrinous 
inflammation  is  spoken  of. 

If  the  effusions  and  corpuscles  make  their  appearance  upon  the  sur- 
face of  a  mucous  membrane,  and  there  is  more  or  less  swelling  and 
desquamation  of  the  epithelial  cells,  the  condition  is  termed  a  catarrhal 

inflammation  (Fig.  39). 

Fig.  39. 


Acute  bronchial  catarrh :  passage  of  leucocytes  through  the  epithelium  of  the  bronchus  between 
the  ciliated  cells.    X  VOO.    (Thoma.) 


Treatment. — The  cardinal  principle  in  the  treatment  of  inflamma- 
tion is  the  removal  of  its  cause.  As  inflammation  is  Nature's  means  of 
ridding  herself  of  an  irritant,  the  removal  of  the  irritant  by  the  operator 
is  the  most  efficient  aid  in  the  process.  As  the  majority  of  inflamma- 
tions are  certainly  due  to  the  action  of  bacteria,  the  removal  of 
bacteria  and  their  products  is  the  principal  aim  of  treatment  (see 
Chapter  VI.). 

Aside  from  the  consideration  of  removing  the  cause,  the  treatment 
of  inflammation  is  directed  to  modifying  or  removing  the  several  condi- 
tions which  give  rise  to  the  symptoms.    The  tissues  are  overloaded  with 


REGENERATION  OF  TISSUES.  85 

exudation  which  the  lymphatic  vessels  cannot  remove ;  the  bloodvessels 
are  distended  by  an  increased  amount  of  blood,  whose  exit  is  l)locked, 
but  which  is  receiving  additions  with  each  pulse-beat,  increasing  the 
pain,  swelling  and  heat.  The  indication  is  clear — relieve  the  stagna- 
tion. The  direct  causative  factor  of  the  stagnation  is  the  vascular  supply ; 
if  the  blood  can  be  made  to  flow  freely  along  the  clogged  veins,  the  flow 
through  the  capillary  area  will  also  be  re-established.  If  less  blood 
is  carried  to  the  part,  there  will  be  no  additional  stagnation.  So  long 
as  the  vascular  congestion  persists  there  is  no  possibility  of  removal 
of  the  effusion  by  the  lymphatics. 

Nancrede  found,  on  dividing  a  vein  upon  the  distal  side  of  an 
area  of  inflammation,  that  after  a  brief  period  the  flow  of  blood  was 
established  through  the  inflamed  area.  Local  bloodletting  by  leeches 
(Gensmer)  produced  even  more  marked  effects.  Drugs  which  stimulate 
the  vasoconstrictors  (ergot),  and  those  which  paralyze  the  constrictors 
(aconite),  lessen  the  blood-pressure  in  the  inflamed  area,  so  that  if 
administered  in  the  early  stages  of  inflammation  they  may  modify  its 
severity.  If,  on  the  contrary,  they  are  administered  after  stasis  occurs, 
they  increase  the  stasis — ergot  actively  and  aconite  passively.  If  the 
flow  of  blood  through  the  inflamed  area  is  re-established  by  local  blood- 
letting, after  the  period  of  stasis,  then  the  arterial  sedatives  are  dis- 
tinctly useful  in  lessening  the  flow  of  blood  to  the  part.^ 

When,  owing  to  vascular  engorgement,  throbbing  pain  is  a  promi- 
nent symptom,  applications  of  cold  are  useful  in  lessening  the  calibre 
of  vessels  and  in  relieving  pain.  But  if  there  be  firm  exudation  and 
marked  stasis,  cold  is  a  detriment.  Heat  then  gives  relief  through 
inducing  a  more  free  flow  of  blood  in  the  collateral  circulation.  Very 
hot  applications  act  as  do  cold  applications,  by  causing  contraction  of 
vessels,  and  may  be  used  to  abort  an  inflammation. 

General  sedatives  are  at  times  demanded  for  the  relief  of  pain. 
Morphia,  used  in  small  and  continued  doses,  not  only  relieves  pain,  but 
causes  a  contraction  of  small  vessels. 

Regeneration  of  Tissues. 
When  the  inflammatory  action  terminates  without  the  formation  of 
pus  a  series  of  changes  is  instituted  which  normally  results  in  a 
reorganization  of  the  area  of  degeneration.  This  is  termed  the  process 
of  repair.  The  pathological  exudations  cease,  the  vessels  resume  their 
normal  tone,  tissue  which  has  died  as  the  result  of  the  inflammation  is 
cast  out  or  is  absorbed  (eaten  by  the  phagocytes)  and  removed,  and  the 
exudate  is  absorbed  by  the  lymphatics.  The  site  of  inflammation  is 
now  filled  with  a  mass  of  indifferent  embryonic  corpuscles,  consisting  in 

'  Warren,  Ibid. 


86  DISTURBANCES  OF  THE   VASCULAR  SYSTEM. 

Fig.  40. 


Isolated  cells  from  a  granulating  wound :  a,  uninuclear  leucocyte ;  ai,  multinuclear  leucocyte ; 
6,  different  shapes  of  uninuclear  formative  cells;  c,  double  nucleated  formative  cells;  Ci, 
multinucleated  formative  cells  ;  d,  formative  cells  in  the  process  of  tissue-formation  ;  e,  com- 
pleted connective  tissue.    Picrocarmine  preparation.    X  500.    (Ziegler.) 


Fig.  41. 


Development  of  a  bloodvessel  by  formation  of  offshoots,  from  preparations  which  were  taken  from 
a  formation  of  inflammatory  granulations  :  a,  b,  c,  d,  different  forms  of  offshoots— some  solid 
(ti,  c),  some  becoming  hollow  (a,  b,  d),  some  simple  («,  d),  some  branching  (&,  c),  some  without 
nuclei  (a,  d),  some  with  nuclei  (b,  c).  Formative  cells  have  applied  themselves  to  the  outside 
of  the  offshoots.    (Ziegler.) 


REGENERATION  OF  TISSUES. 


87 


part,  no  doubt,  of  embryonic  cells  of  the  several  tissues  destroyed  by 
the  inflammatory  process,  among  which  are  numbers  of  leucocytes  (Fig. 
40).  It  is  out  of  this  embryonic  tissue  that  a  reproduction  of  the  several 
tissues  takes  place.  It  is  to  be  remembered  that  while  any  of  the 
several  connective  tissues — the  tissues  of  mesoblastic  origin — may  be 
reproduced  from  this  embryonic  tissue,  epithelial  tissue  is  never  repro- 
duced save  from  epithelium. 

The  embryonic  tissue  soon  acquires  a  new  blood-supply  (Fig.  41). 
In  the  endothelial  cells  of  the  walls  of  the  capillaries  about  the  part 
division  of  the  cell-nucleus  takes  place,  and  by  the  reproductive  process 


Fig.  42. 


O    O    o    o 

^   o    o  Q  o  On 


A  granulating  surface  :  a,  layer  of  pus ;  b,  granulation-tissue  witli  loops  of  bloodvessels  ;  c,  com- 
mencing development  of  the  granulation-tissue  into  a  flbrillated  structure.  X  200.  Diagram- 
matic.   (Rindfleisch.) 

a  bud  grows  from  the  capillary  wall ;  by  repeated  reproductions  solid 
columns  of  cell-substance  are  formed  which,  joining  columns  from  other 
capillaries,  form  loops,  the  centre  of  the  columns  becomes  hollowed  out, 
forming  tubes  which  transmit  blood — i.  e.,  new  capillaries  are  formed. 
The  mass  of  embryonic  tissue  becomes  thus  permeated  by  a  network  of 
new  capillaries  (Fig.  42).  The  tissue  in  its  present  state  is  known  as 
granulation-tissue.  The  cells  of  granulation-tissue  are  partly  hyper- 
trophied  tissue-cells  and  partly  mono-  and  polynucleated  leucocytes.^ 

^  Ziegler's  Oenerul  Pathology, 


88  DISTURBANCES  OF  THE   VASCULAR  SYSTEM. 

When  the  cells  have  organized  and  are  transformed  into  connec- 
tive-tissue forms  and  arrangement,  contraction  takes  place,  and  most  of 
the  new  bloodvessels  are  obliterated ;  the  new  tissue  becomes  pale — it  is 
a  cicatrix.  The  indiiferent  embryonic  cells  may  have  the  function  of 
forming  any  of  the  connective  tissues.  If  cartilage  is  to  be  formed, 
chondrification  takes  place  about  the  specialized  cells.  If  bone  is  to  be 
formed,  each  cell  becomes  an  islet  around  which  calcification  proceeds. 
If  ei^ithelium  have  been  lost,  the  epithelium  existing  undergoes  prolif- 
eration, growing  inward  from  the  sides  of  the  area  denuded  of  epithehal 
covering,  until  a  new  epithelial  surface  is  formed. 


CHAPTER   VI. 

INFECTIVE  INFLAMMATIONS:    SUPPURATION,   ABSCESS, 
FEVERS,   SEPTICEMIA,   AND  PYEMIA. 

An  infective  inflammiition  may  be  defined  as  a  condition  in  which 
the  phenomena  described  under  the  head  of  inflammation  are  caused  by 
or  characterized  by  the  presence  and  development  of  pathogenic  bacteria. 
In  the  light  of  Metchnikoif's  studies,  many  pathologists  maintain  that 
inflammation  is  always  an  infective  process  ;  that  it  is  in  consequence 
of  the  presence  of  bacteria  that  the  phenomena  of  inflammation  occur. 
This  view  is  not  entirely  subscribed  to,  particularly  by  German  patholo- 
gists ;  but  the  belief  is  daily  gaining  ground  among  the  pathologists  of 
other  nationalities  that  Metchnikoif 's  theory,  even  though  not  meeting  all 
conditions,  furnishes  the  most  satisfactory  explanation  of  the  etiology  of 
inflammation  ever  presented.  This  theory  is,  in  substance,  "  that  the  pro- 
cess of  inflammation  is  one  of  the  factors  in  organic  evolution.  Begin- 
ning with  the  amoeba,  this  simple  organism,  the  analogue  of  the  white 
blood-corpuscles  has  the  power  of  englobing  and  digesting  solid  matters, 
such  as  bacteria,  with  wdiich  it  is  brought  in  contact."  In  animals  pro- 
gressively higher  in  the  zoological  scale,  wandering  cells  of  the  body, 
similar  to  the  white  blood-corpuscles,  exhibit  this  property,  until  in 
the  mammalia,  including  man,  Metchnikoif  holds  that  the  same  cells 
have  as  a  distinctive  function  the  attacking  and  removing  of  foreign 
substances,  pathogenic  organisms  included,  which  gain  access  to  the 
body.  As  noted  in  discussing  the  subject  of  bacteria  (see  Cheraotaxis), 
special  properties  of  the  invading  substance  may  determine  whether  it  is 
to  be  attacked  and  removed  by  the  white  blood-corpuscles,  or  whether  it 
is  avoided  by  these  same  cells.  He  suras  up  his  investigations,  made 
upon  all  classes  of  animals,  and  after  reviewing  the  experiments  of  Vir- 
chow,  Samuel,  and  Cohnheim,  with  the  dictum  that  "  The  essential  and 
'primary  element  in  typical  inflammation  consists  in  a  reaction  of  the  phago- 
cytes against  a  harmful  agent."  ^ 

MetchnikoflF  and  his  followers  maintain  that  the  changes  which  occur 
in  the  absence  of  bacteria  are  not  characterized  by  the  flocking  and  dia- 
pedesis  of  leucocytes  ;  that  this  latter  phenomenon  is,  in  fact,  the  distin- 
guishing feature  of  inflammation  ;  and  that  conditions  following  injuries 
of  other  kinds  belong  to  the  hypersemias. 

^  Metchnikoff,  Comparative  Pathology  of  Inflammation,  1893. 


90  INFECTIVE  INFLAMMATIONS. 

Leaving  open  the  question,  whether  true  inflammation  can  occur 
in  the  absence  of  bacteria,  it  is  certain  that  a  vast  majority  of  inflam- 
mations are  due  to  or  are  characterized  by  the  development  of  patho- 
genic organisms  at  some  point — the  area  of  infection.  That  is,  when 
pathogenic  bacteria  gain  entrance  to  the  body  and  find  a  suitable  soil, 
they  undergo  multiplication,  they  cause  degeneration  in  the  tissues ; 
inflammation  with  death  of  more  or  less  tissue,  and,  after  a  period,  re- 
generative changes  occur.  During  the  period  of  their  growth  sub- 
stances are  formed  which,  being  taken  into  the  circulation,  act  as  poi- 
sons (see  Fever,  Septicaemia,  and  Pysemia).  For  example,  in  typhoid 
fever  a  specific  bacillus  gaining  access  to  the  glands  of  Peyer's  patches, 
under  favorable  conditions  multiplies  and  causes  degeneration,  inflam- 
mation, and  cellular  necrosis  of  the  part,  forming  ulcerous  patches. 
During  the  period  of  multiplication  toxic  substances  are  formed  which,^ 
when  absorbed  and  carried  by  the  circulatory  fluids  throughout  the 
body,  cause  the  train  of  symptoms  peculiar  to  typhoid  fever.  The  na- 
ture of  the  local  changes  induced  and  the  general  symptoms  accompany- 
ing infection  depend  upon  the  nature  of  the  infecting  organism.  The 
effects  of  pathogenic  organisms  as  a  class  are,  however,  those  above 
noted :  local  tissue-degeneration,  inflammation,  cellular  necrosis,  with 
symptoms  of  general  poisoning  ;  at  a  later  period  regenerative  changes 
occur  which  heal  the  injured  part.  This  naturally  divides  the  study  of 
infection  into  two  heads  :  first,  local  effects  ;  secondly,  general  symptoms. 

Suppuration. 

By  far  the  most  common  and  universal  causes  of  infective  inflam- 
mations are  the  pyogenic  cocci  (p.  45),  organisms  which,  gaining  access 
to  the  interior  of  the  body,  cause  the  formation  of  pus.  According  ta 
their  mode  of  grouping,  these  cocci  are  divided  into  two  classes :  first, 
the  staphylococci ;  secondly,  the  streptococci.  The  staphylococci  are 
subdivided  according  to  the  color  of  their  colonies  in  a  culture-medium  r 
the  staphylococci  producing  orange-colored  colonies  are  called  staphylo- 
cocci pyogenes  aureus  ;  those  forming  whitish  colonies,  the  staphylococci 
pyogenes  albus ;  those  causing  lemon-colored  growths,  the  staphylococci 
pyogenes  citreus  ;  those  giving  green  colonies,  the  staphylococci  pyo- 
genes viridis.  The  staphylococcus  pyogenes  aureus  appears  to  be  every- 
where. 

Bacteria  may  gain  entrance  to  the  body  through  v/ounds  of  the  skin 
or  of  mucous  membranes,  or  through  any  break  or  abrasion  of  these 
surfaces.  They  enter  nearly  every  wound  made,  unless  special  precau- 
tions are  taken  to  exclude  them  ;  they  are  inhaled,  and  may  be  taken 
into  the  body  from  the  respiratory  tract ;  they  may  be  taken  up  from 
the  alimentary  tract. 


PLATE  II. 


Abscess  in  Kidney  of  Rabbit  after  Intravenous  Injection  into  an 
Ear-vein  of  Culture  of  Pyogenic  Cocci.  Dense  mass  of  cocci 
surrounded  by  area  of  coagulation  necrosis  due  to  their  toxic 
activity.     Outside  this  a  zone  of  phagocytes. 


SUPPURATION.  91 

It  is  of  extreme  importance  to  remember  that  a  condition  of  perfect 
health  in  cells,  tissues,  and  the  body,  is  a  safeguard  against  the  attacks 
of  any  organisms  which  may  gain  entrance  to  the  body  ;  and,  vice  versa, 
a  susceptibility  to  their  action  is  produced  in  the  body,  in  its  tissues,  or 
in  its  cells,  by  a  condition  of  debility  of  a  part.  This  is  notably  true 
of  hyperemia ;  a  part  which  is  suffering  from  the  degree  of  irritation 
which  causes  hypersemic  debility,  will  fall  a  ready  victim  to  the  action 
of  organisms  which  would  probably  not  affect  it  in  a  condition  of  health. 
To  take  a  sim})le  example  :  the  mouth  of  a  sebaceous  gland  of  the  skin 
becoming  occluded,  there  is  no  escape  for  the  secretion,  which  accumu- 
lates and  changes  in  character ;  owing  to  the  mechanical  irritation  of 
accumulated  ]iroducts,  secretion  is  at  first  increased,  until  the  acini 
and  duct  of  the  gland  become  much  dilated ;  the  part  becomes  like  a 
foreign  body,  is  a  source  of  irritation  and  active  hyperiemia  results.  Due 
to  this  cause,  and,  no  doubt,  to  fermentative  changes  which  occur  in  the 
accumulated  secretion,  a  condition  of  lessened  resistance  is  produced. 
The  ever-present  staphylococcus  pyogenes  aureus  gains  access  to  the 
gland,  multiples,  and  causes  the  changes  characteristic  of  an  infective 
inflammation.  The  phenomena  of  inflammation  occur — heat,  redness, 
pain,  and  swelling ;  there  is  a  diapedesis  of  white  blood-corpuscles 
with  a  fibrinous  etfiision,  which  in  the  presence  of  injured  leucocytes 
coagulates.  In  the  struggle  between  the  invading  bacteria  and  the 
leucocytes  myriads  of  the  latter  have  succumbed — have  died ;  the 
organisms  secreting  or  excreting  a  substance  capable  of  changing  the 
(coagulated)  albuminous  effusion  into  liquid  peptone,  there  results  a 
fluid  holding  in  suspension  the  leucocytes  which  have  died,  and  the 
detritus  of  the  tissue  destroyed  in  the  struggle  -,  the  tissue-destruction 
proceeds  in  all  directions,  advancing  most  readily  in  the  lines  of 
least  resistance,  until  the  accumulated  fluid,  with  the  cells  and  detritus, 
are  discharged.  Occurring  in  a  very  small  area,  the  process  describes 
the  origin,  course,  and  termination  of  a  pimple  ;  if  a  larger  territory 
is  involved,  a  boil ;  in  both  cases  the  condition  is  one  of  abscess.  The 
fluid  discharged  from  the  abscess  is  called  pus.  It  consists  of  in- 
flammatory effusion,  now  fluid,  having  been  transformed  into  pep- 
tone, the  dead  leucocytes,  dead  bacteria,  and  the  remnants  of  broken- 
down  tissue.  This  is  the  essential  process  of  suppuration  in  any  part :  the 
entrance  of  pyogenic  organisms  into  the  tissues,  the  exciting  of  inflam- 
mation at  some  point  of  lessened  resistance — a  locus  minoris  resistentke, 
the  death  of  tissues  and  leucocytes,  the  peptonizing  of  inflammatory 
effusions  and  breaking  down  of  dead  tissue,  and  the  escape  of  the.  fluid 
thus  constituted  (Plate  II.). 

It  does  not  always  happen  that  the  pus  finds  escape,  either  naturally 
or  through  surgical  aid  ;    the  patient  may  die  before  this  occurs   (see 


92  INFECTIVE  INFLAMMATIONS. 

Septicaemia),  or  the  tissues  beyond  the  seat  of  pus-formation,  those  in 
which  the  irritation  does  not  exceed  constructive  hypersemia,  may  form 
a  boundary-wall  which  the  organisms  fail  to  break  down  and  thus  die — 
starved  out ;  the  abscess-contents  undergo  changes,  a  cheesy  or,  in  some 
cases,  a  calcareous  mass  marking  the  site  (see  Degenerations). 

While  the  staphylococci  cause,  as  a  rule,  the  circumscribed  destruc- 
tion of  tissue  described,  the  streptococci,  as,  for  example,  the  strepto- 
coccus of  erysipelas,  tend  to  multiply  laterally,  following  the  tortuosites 
of  the  connective  tissue  of  the  skin.  They  give  rise  to  a  progressively 
spreading  violent  inflammation,  but  do  not  cause  a  marked  peptonizing 
of  effusions  and  dead  tissue — /.  e.,  but  little  pus  is  formed. 

Cause. — The  cause  of  suppuration  is  the  develojjment  in  tissues  of 
jDyogenic  organisms. 

Symptoms. — The  symptoms  of  suppuration  are  both  general  and 
local.  The  local  symptoms  are,  first,  those  of  inflammation.  At  the 
height  of  the  inflammation  the  apex  of  the  swelling,  hitherto  of 
marked  firmness,  gives  a  feeling  of  lessened  resistance,  and  later 
acquires  a  boggy  softness.  If  the  swelling  be  of  marked  size,  dis- 
tinct fluctuation  may  be  felt,  showing  the  presence  of  fluid ;  the  apex 
of  the  swelling  bursts,  giving  vent  to  the  abscess-contents,  when  the 
inflammatory  symptoms  rapidly  subside,  the  tissues  lose  their  hardness, 
and  usually  regenerative  changes  occur,  causing  the  obliteration  of  the 
abscess-cavity  and  tract ;  or  it  may  be  that  pus-formation  continues  after 
the  subsidence  of  the  inflammatory  symptoms.  The  area  of  tissue-loss 
is  called  the  abscess-cavity ;  the  pathway  leading  from  the  cavity  to  the 
point  of  discharge  is  called  the  fistula. 

General  Sy:mptoms. — The  general  symptoms  of  suppuration  are 
caused  by  the  absorption  of  the  products  of  bacterial  growth.  These 
symptoms,  if  the  suppuration  be  extensive,  may  be  ushered  in  with  a 
chill ;  there  may  be  fever  as  high  as  104°  F.,  a  full,  bounding  pulse, 
and  all  the  accompaniments  of  fever.  In  some  cases  of  delayed  evac- 
uation of  the  abscess  there  may  be  evidence  of  profound  poisoning. 

Prog-nosis. — As  a  rule,  abscesses  tend  to  spontaneous  recovery  after 
evacuation,  and  in  case  a  persistent  discharge  remains  it  is  to  be  sus- 
pected that  some  portions  of  dead  tissue  have  not  been  discharged,  and 
that  in  minute  crypts  or  crevices  bacteria  still  develop.  The  occurrence 
of  rigors  (chills)  and  high  fever  is  a  danger-signal.  A  fluttering,  weak 
pulse  and  clammy  extremities  following  upon  the  primary  fever  are  evil 
omens. 

Treatment. — When  it  is  considered  that  the  disease  symptoms  and 
dangers  attendant  upon  the  process  of  suppuration  are  due,  in  the  first 
place,  to  the  pyogenic  organisms,  and  that  the  presence  of  pus  and  dead 
tissue  is  a  source  of  debility  and  a  detriment  to  the  process  of  regenera- 


ULCERATION.  93 

tion,  it  is  at  once  clear  that  the  therapeutic  indication  is  to  rid  the  body 
of  all  of  these  substances ;  that  is,  the  evacuation  of  the  pus  is  always 
the  measure  to  be  adopted. 

As  soon  as  it  is  determined  that  pus  is  present  in  any  accessible 
situation  whatever,  it  should  be  given  vent.  If  it  be  an  abscess  point- 
ing', as  in  a  boil  or  over  the  root  of  a  tooth,  a  sharp-curved  bistoury 
should  be  passed  tiirough  the  top  of  the  swelling  and  by  a  drawing 
motion  a  linear  cut  made,  giving  free  exit  to  the  pus.  Even  though 
the  pus  be  not  nearing  a  natural  vent,  if  it  is  enclosed  in  the  cancellated 
tissue  of  bone  (osteomyelitis),  or,  as  in  alveolo-dental  abscess,  confined 
under  the  maxillary  periosteum  (see  chapter  on  Alveolar  Abscess),  or  be 
under  the  periosteum  of  the  finger  or  elsewhere,  an  opening  should  be 
freely  made  into  the  infected  area.  As  a  rule,  healing  is  spontaneous 
after  the  opening  of  an  abscess,  the  discharge  lessening  gradually,  and 
the  cavity  and  exit  being  filled  with  granulation-tissue.  In  case  the 
abscess-walls  contain  crypts  in  which  bacteria  may  multiply,  it  may  be 
necessary  to  use  antiseptic  Avashes  to  reach  and  destroy  them.  Hydro- 
gen dioxid,  in  a  15  volume  or  3  per  cent,  aqueous  solution,  is  used  to 
syringe  out  the  cavity.  Should  the  opening  of  the  cavity  be  large,  and 
there  be  danger  of  reinfection,  it  is  advisable  to  pack  the  cavity  with 
gauze  impregnated  with  iodoform  or  aristol,  or  with  the  more  recent 
iodin  preparation,  nosophen.  Any  dead  tissue  in  the  abscess  must  be 
mechanically  removed,  as  regeneration  will  be  delayed  or  prevented  so 
long  as  the  necrosed  parts  are  suffered  to  remain. 

ULCERATION. 

The  development  of  the  pyogenic  organisms  upon  a  free  surface 
causes  tissue-degeneration  and  death,  as  described  under  abscess  ;  in  fact, 
an  abscess  is  a  confined  ulcer. 

Numerous  forms  of  pathogenic  organisms  are  capable  of  causing 
tissue-degeneration  and  death  of  a  mucous  or  skin  surface.  If  infection 
takes  place  through  a  hair-follicle,  or  if  organisms  develop  npon  an 
abrasion,  or  in  the  epithelium,  in  conditions  of  general  or  local  debility, 
the  epithelium  is  destroyed  over  an  area,  and  in  the  subepithelial  tis- 
sues the  organisms  multiply  and  cause  tissue-loss.  If  the  organisms  be 
pyogenic — and  ulcerous  surfaces  are  usually  infected  by  these  bodies — 
pus  is  formed.  Under  some  conditions,  as  in  debilitated  and  neglected 
children,  the  ulcerous  process  may  spread  rapidly,  as  of  the  cheek  in 
cancrum  oris  ;  or  when  specific  bacilli,  which  excite  mucdi  swelling  and 
quick  death  of  the  tissues  of  the  cheek  proliferate,  causing  the  condition 
called  noma. 

Treatment. — The  general  treatment  of  ulcers  is  to  destroy  the 
infecting  organisms  by  antiseptic  washes,  such  as  a  1  :  2000  solution  of 


94  INFECTIVE  INFLAMMATIONS. 

mercuric  chlorid  in  hycli-ogen  clioxid,  and  subsequently  washing  the  sur- 
face of  the  ulcer  with  some  powerful  antiseptic  which  destroys  the 
superficial  tissues  and  the  bacteria  in  them  ;  for  example,  concentrated 
carbolic  acid.  The  exposed  surface  is  next  coyered  with  an  antiseptic 
powder — iodoform,  aristol,  or  nosophen  (see  section  on  Pharmacology) — 
and  then  the  surface  is  to  be  protected  from  the  access  of  organisms 
nntil  the  regeneratiye  process  has  healed  the  breach.  It  is  to  be 
remembered,  in  this  connection,  that  the  reproduction  of  epithelium  is 
from  the  epithelial  boundary  of  the  ulcer,  for  epithelium  cannot  develop 
from  any  but  epithelial  tissue. 

OSTEOMYELITIS. 

There  is  one  kind  of  sujjpuration  of  more  than  ordinary  interest 
to  the  dental  practitioner,  as  beyond  doubt  many  cases  of  maxillary 
abscess  should  be  classed  under  this  head — osteomyelitis,  an  inflamma- 
tion of  the  bone-marrow. 

Causes. — In  conditions  of  debility  pyogenic  organisms,  notably  the 
staphylococci,  and  occasionally  streptococci  or  pneumococci,  or  the  bacil- 
lus tuberculosis,  and  in  special  cases  the  typhoid  bacillus,^  gain  access 
to  the  cancellated  tissue  of  bone ;  they  cause  a  thrombosis  of  the  ves- 
sels about  the  area  of  infection,  the  bone-cells  die,  and  suppuration 
ensues. 

Patholog-y  and  Morbid  Anatomy. — In  consequence  of  the  growth 
of  the  organisms  the  adjoining  vessels  become  thrombosed,  the  cells  of 
the  bone  die — undergo  coagulation-necrosis,^  and  the  tissues  are  rapidly 
broken  down  into  pus.  The  process  spreads  until  the  bone  is  perforated 
and  the  pus  finds  exit  beneath  the  periosteum,  which  it  separates  from 
the  bone  unless  the  exit  be  immediate,  and  necrosis  of  that  portion  of 
the  cortical  bone  results.  If  the  process  approach  the  nutrient  artery 
of  the  bone,  thrombosis  of  that  vessel  occurs ;  and  if  it  be  a  trunk  of 
large  size  and  of  very  limited  anastomoses,  as  in  the  inferior  dental 
artery,  necrosis  of  the  bone  results.  The  case  is  one  of  abscess  in 
peculiar  anatomical  situation,  where  the  ordinary  phenomena  of  inflam- 
mation can  not  be  manifested. 

Symptoras. — The  general  symptoms  of  this  condition  are  those  of 
septic  infection,  combined  with  local  evidences  of  marked  disorder. 
There  is  debility  with  sharp  but  ill-located  pain,  which  may  be  followed 
by  a  chill,  high  fever,  and  a  local  inflammatory  reaction  of  much 
severity ;  the  fever  assumes  the  adynamic  type.  The  pain  becomes 
localized  in  the  affected  bone,  and  the  duration  of  the  symptoms  will 
depend  primarily  upon  the  time  required  for  the  escape  of  pus,  natu- 
rally or  through  surgical  aid.     When  the  superficial  layers  of  a  bone 

'  Park's  Surgery,  vol.  i.  ^  Ibid. 


FEVER  95 

fire  affected  or  tlie  infection  is  snlipcriosteal,  it  constitutes  the  condition 
known  as  acute  infectious  periostitis. 

Treatment. — The  essential  principle  of  treatment  in  all  cases  as 
soon  as  recognized  is  to  uain  access  to  the  infected  parts  by  incis- 
ing and  drilling  instruments,  drain  the  cavity,  remove  dead  tissue, 
and  sterilize  the  cavity. 

Fever. 

The  term  fever  is  applied  to  a  condition  the  most  prominent  feature 
of  which  is  an  elevation  of  the  bodily  temperature  above  the  normal, 
37°  C.  To  constitute  a  fever  this  rise  in  temperature  must  continue  for 
some  length  of  time. 

Causes. — Fevers  are  commonly  caused  by  the  presence  in  the  circu- 
latory fluids  of  substances  which  act  as  poisons  upon  probably  the  nerve- 
centres  controlling  heat-production.  As  a  rule,  the  offending  substance 
is  a  poison  generated  in  the  body  through  the  action  of  micro-organisms. 
The  character  and  type  of  the  fever  are  determined  by  the  nature  of  the 
offending  substances — /.  e.,  the  variety  of  infection. 

Classes. — Fevers  are  divided  into  periodic  or  continued,  according 
as  to  whether  there  is  a  periodical  fall  of  temperature  and  a  subsequent 
rise,  or  whether  the  fever  continues  practically  unabated  from  the  begin- 
ning to  the  termination  of  a  disease.  Fevers  are  classed  in  severity 
according  to  the  maximum  temperature  and  again  according  to  their 
duration.  A  temperature  of  100.5°  to  101.3°  F.  is  called  slightly  febrile  ; 
101.3°  to  103°  F.,  moderate  fever  ;  103°-105°  F.,  marked  fever.  A  tem- 
perature above  106°  is  termed  hyperpyrexia. 

Symptoms. — The  most  characteristic  symptom  of  fever  is  the  eleva- 
tion of  temperature  ;  accompanying  this  there  is  an  increased  frequency 
of  the  pulse.  In  acute  inflammatory  diseases  the  pulse  is  full  and  bound- 
ing, the  eyes  injected,  the  bowels  constipated,  and  the  urine  scanty,  con- 
taining an  excess  of  urea.  On  standing,  the  urine  throws  down  a  brick- 
dust  deposit  (urates).  In  fevers  of  a  lower  type,  or  in  many  fevers 
which  began  as  described,  the  high,  bounding  pulse  is  succeeded  by  a 
soft,  quick  pulse  and  evidences  of  great  debility.  In  fevers  in  which 
the  temperature  runs  high  there  is  commonly  evidence  of  intoxication, 
more  or  less  delirium,  and  reflex  muscular  action.  AVith  a  persistent 
temperature  and  a  pulse  becoming  softer  and  more  frequent,  there  is 
increasing  debility. 

Patholog-y  and  Morbid  Anatomy. — In  all  cases  of  continued  high 
temperature  the  fat  of  the  body  rapidly  disappears  and  granular  degen- 
eration occurs  in  the  muscles  and  viscera  of  the  body.  If  the  fever  be 
long  continued  and  of  an  adynamic  type,  this  degeneration  may  become 
marked.     Its  occurrence  in  the  muscles  of  the  heart  is  common  and  is 


96  INFECTIVE  INFLAMMATIONS. 

an  element  of  danger.  There  are  an  increase  in  the  amount  of  carbon 
dioxid  formed  and  exhaled  from  the  body,  and  an  increased  amount  of 
oxygen  inhaled.  This,  with  the  increase  of  urea,  the  product  of  the 
oxidation  of  nitrogenous  tissues  (muscles,  glands,  etc.),  indicates  that 
the  oxidation  of  the  tissues  is  largely  increased;  hence  the  elevation 
of  temperature.  As  repair  does  not  equal  waste  in  fevers,  the  nutri- 
tive processes  being  profoundly  disturbed,  the  essential  elements  of  the 
tissues  suffer  from  the  increased  oxidation  and  undergo  degenerative 
changes. 

Prognosis. — The  higher  the  temperature  and  the  longer  it  continues 
the  greater  drain  there  is  upon  the  vital  forces.  As  a  rule,  a  temperature 
of  106°  F.  persisting  more  than  twenty- four  hours  presages  death.  If 
the  vital  forces  flag  and  the  heart-action  becomes  weakened,  and  if 
there  be  evidence  of  profound  intoxication,  such  as  twitching  of  tendons, 
low,  muttering  delirium,  and  a  clammy  surface,  the  outlook  is  bad. 
Favorable  signs  are  falling  temperature,  a  clear  eye,  tongue  losing  its 
coating,  free  action  of  the  bowels,  free  perspiration,  free  action  of  the 
kidneys,  and  a  good  vascular  tension. 

Treatment. — In  the  light  of  present  knowledge,  efforts  should 
first  be  made  to  discover  the  nature  of  the  cause  of  the  fever  and 
to  remove  it,  if  possible.  If  not,  attention  should  be  directed  to  main- 
taining the  vital  forces  until  the  body  rids  itself  of  the  offending  causes. 
As  many  fevers  are  self-limited  in  course  and  duration,  this  latter  treat- 
ment becomes  an  important  consideration.  Temperature  should  be  kept 
within  safe  limits  by  the  administration  of  antipyretics,  when  the  con- 
dition of  the  heart  will  permit  their  being  used,  and  also  by  cool  spong- 
ing or  cool  baths.  The  action  of  the  heart  should  be  sustained  by 
the  administration  of  concentrated  nutriment,  and  by  stimulants  when 
necessary.     The  bowels  must  be  kept  open. 

In  any  form  of  fever  there  is  no  therapeutic  measure  comparable 
with  removal  of  the  cause,  provided  this  be  discoverable,  identified,  and 

removable. 

Septicemia. 

Septicsemia  is  a  condition  in  which  septic  matter  is  present  in  the  cir- 
culating fluids  of  the  body,  and  causes  manifestations  of  widespread 
disorder. 

"  The  essence  of  septicaemia  is  a  poisoning  of  the  organism  by  toxins, 
toxalbumins,  ferments,  and  other  products  of  bacterial  decomposition — 
i.  c,  it  is  septic  intoxication."  ^ 

Varieties. — Conditions  of  septicaemia  maybe  classified,  according  to 
the  severity  of  the  symptoms,  as  mild  septic  intoxication,  septic  poison- 
ing, and  pyaemia.  The  nature  and  severity  of  the  intoxication  depend 
^  Ziegler,  General  Pathology,  1895. 


SEPTICAEMIA.  97 

upon  the  nature  of  the  poison — /.  e.,  the  variety  of  infecting  organisms. 
The  effects  range  from  a  slight  increase  of  bodily  temperature  to  a  pro- 
found disturbance  of  the  vital  functions  which  ushers  in  death.  They 
vary  again  from  a  transient  intoxication  to  prolonged  and  constantly 
increasing  evidences  of  poisoning. 

Causes. — Many  of  the  cases  described  under  the  head  of  fevers 
might  be  fitly  included  under  the  head  of  septic  intoxication — in- 
deed, fever  is  one  of  the  prominent  evidences  of  septic  intoxication  and 
their  causes  are  similar.  The  causes  of  septic  intoxication  are  the  ab- 
sorption from  one  or  more  foci  of  bacterial  development  of  toxic  sub- 
stances which  have  been  generated  as  the  result  of  the  vital  processes 
of  the  organisms.  Pathogenic  organisms,  in  addition  to  local  tissae- 
degenerations  caused  by  their  local  action,  induce  these  general  symp- 
toms of  disorder  by  the  character  of  the  substances  produced  by  them. 
Bacteria  may  gain  entrance  to  the  body  at  some  point,  as  at  a  wound,  be 
taken  up  from  some  portion  of  the  alimentary  tract  or  from  the  lungs, 
and  Avhile  causing  but  comparatively  slight  local  evidences  of  disease  at 
the  point  of  entry,  may  develop  in  other  portions  of  the  body  and  gene- 
rate toxic  substances  in  such  situations.  Miller^  has  recorded  several 
forms  of  bacteria  found  in  the  human  mouth  which  bring  about  pro- 
nounced septic  poisoning  when  injected  into  the  bodies  of  animals. 

Symptoms. — The  symptoms,  both  general  and  local,  of  septic 
infection,  as  stated,  depend  upon  the  character  of  the  poison  in 
the  circulation — /.  e.,  by  the  variety  of  organism  infecting.  This 
may  belong  to  any  of  the  classes  of  bacteria  ca])able  of  developing  in 
any  part  of  the  body.  It  is  only  necessary  that  it  be  some  form  capable 
of  transforming  nitrogenous  substances  into  simpler  bases,  which,  if 
they  gain  entrance  to  the  circulation  from  the  tissues,  alimentary  canal, 
or  respiratory  tract,  cause  manifestations  of  the  action  of  specific  poisons. 
This  is  best  illustrated  by  an  examination  of  the  products  formed  by  the 
progressive  decomposition  of  albumin.  It  is  first  peptonized,  and,  as 
pointed  out  by  Brunton,"  peptones  directly  injected  into  the  blood  cause 
poisoning.  The  substances  formed  in  wounds,  even  those  which  go  on 
to  quick  recovery,  frequently  cause  an  elevation  of  temperature  when 
absorbed.  The  formation  of  compound  ammonias  (ptomains)  is  a  suc- 
ceeding stage  of  decomposition,  in  which  such  substances  as  sepsin, 
neuridin,  tetanin,  and  ethyldiamin  are  formed,  which  are  all  active 
poisons.  Next,  simpler  substances  are  formed,  leucin  and  tyrosin,  with 
the  methyl-amins,  and  afterward  such  aromatic  products  as  indol,  the 
cresols,  etc.  Many  of  these  substances  may  cause  evidences  of  poi- 
soning. Some  of  them  are  formed  in  the  alimentary  canal,  some 
in  the  tissues,  and  if  they  are  absorbed  and  not  promptly  eliminated, 

^  Dental  Cosmos,  Sept.,  Oct.,  and  Nov.,  1891.  '■'  Croonian  Lectures,  1888. 

7 


98  INFECTIVE  INFLAMMATIONS. 

cause  toxic  symptoms.  Pathogenic  bacteria,  such  as  the  typhoid  bacil- 
lus, the  bacillus  of  tetanus,  the  bacillus  of  diphtheria,  and  others,  cause 
the  formation  of  albuminous  bodies,  allied  to  ptomains,  much  more  pois- 
onous than  the  latter;  these  substances  have  been  called  toxins  or  tox- 
albumins  (Brieger). 

The  general  symptoms  of  septicsemia  may  be  described  as,  first,  affec- 
tion of  the  nearest  lymphatic  glands,  in  which  the  organisms  become 
lodged.  Infective  inflammation  occurs  ;  there  is  more  or  less  fever,  the 
height  and  character  of  which  vary  with  the  specific  organism.  In  the 
more  pronounced  cases  chills  occur.  There  occur  diarrhoea,  and,  as 
a  rule,  evidences  of  profound  debility ;  the  heart-action  and  the  pulse 
become  rapid  and  weak,  a  clammy  skin  is  noted,  and  disorder  of  the 
central  nervous  system  is  present.  If  the  infection  occur  from  a  wound 
or  an  evident  focus  of  inflammation,  the  wound-discharges  become  put- 
rid— i.  e.,  show  evidences  of  progressive  decomposition. 

Treatment. — The  first  consideration  in  treatment  is  the  removal  of 
the  cause  if  possible,  and  the  disinfection  of  the  local  disease-focus. 
Failing  in  this,  or  coincidently  with  it,  the  principle  of  therapeutics  is 
to  sustain  the  vitality  of  the  patient  until  the  eliminative  functions  of 
the  body  have  disposed  of  the  poisonous  substances  and  their  genera- 
tors (the  micro-organisms).  The  general  nutrition  is  to  be  supported 
by  concentrated  nutriments,  beef  peptonoids,  protonuclein,  sterilized 
milk,  etc.  The  flagging  heart-action  is  to  be  supported  by  stimulants — 
alcohol  and  strychnia.  Brandy  or  whiskey  is  administered  until  the 
heart's  action  is  found  to  grow  more  steady  and  vigorous.  The  intes- 
tinal tract  is  to  be  kept  clear,  and  intestinal  antiseptics  adniinistered — 
salol,  naphthalin,  and  /3-naphthol.  The  temperature  is  kept  within 
bounds  by  large  doses  of  quinine  and  cool  sponging.  The  mouth  is  to 
be  freely  sprayed  with  strong  antiseptics  :  hydrogen  dioxid,  listerine, 
formalin  (1   per  cent.). 

Pyemia. 

The  word  pysemia  (Greek  puon,  pus,  and  hcema,  blood)  does  not 
imply  the  presence  of  pus  in  the  blood,  as  might  be  inferred,  but  is  used 
to  designate  a  condition  in  which  there  is  Mddespread  pus-formation  in 
areas  of  the  body,  each  suppurating  focus  being  at  some  point  of  the 
circulatory  system.  Toxic  substances  are  formed  at  such  foci,  and  com- 
plicate a  general  septicsemia ;  the  condition  has  been  called  septico- 
pysemia.^ 

Causes. — Pyogenic  organisms,  exercising  their  specific  action  upon 
the  walls  of  bloodvessels,  cause  inflammation  of  the  walls  and  coag- 
ulation of  the  contained  blood,  which  coagulum  becomes  infected  by  the 

^  Ziegler. 


PY^3nA.  99 

organisms.  Portions  of  the  coagulum  become  detached  and  are  carried 
along  the  bloodvessels,  setting  np  snppnrative  processes  wherever  the 
fragment  happens  to  find  lodgement.  They  are  carried  via  veins  to  the 
kings,  and,  stopping  there,  snppnration  ensues ;  carried  into  the  pul- 
monary veins,  they  reach  the  heart,  Avhere  they  may  excite  inflamma- 
tion ;  carried  into  the  arteries,  each  point  of  arrest  becomes  a  centre  of 
suppuration.  These  organisms  may  find  their  Avay  into  the  circulation 
in  the  manner  described  from  any  area  of  suppuration  in  the  body  in 
which  veins  may  be  engaged. 

Symptoms. — The  symptoms  of  pyaemia  are,  in  general,  those  of 
septicaemia,  but,  as  a  rule,  their  appearance  is  more  delayed  from  the 
date  of  the  reception  of  an  injury  or  the  outbreak  of  the  primary  sup- 
puration. The  onset  of  pyaemia  is  usually  by  a  chill  or  a  succession  of 
chills.  Each  fresh  area  of  pus-formation  is  believed  to  be  announced  by 
a  chill  and  a  rise  of  temperature.  The  temperature  is  subject  to  remis- 
sions, and  sudden  variations  in  its  height  are  noted.  The  general  symp- 
toms are  those  of  an  adynamic  fever.  Local  symptoms  appear  accord- 
ing to  the  point  of  lodgement  of  septic  emboli.  Pus-centres  may  be 
found  in  the  lungs,  and  cause  symptoms  of  dyspnoea  ;  collections  fre- 
quently occur  in  joints,  causing  loss  of  mobility  ;  the  swellings  being 
apparent,  eruptions  appear  on  the  skin  ;  typhoid  symptoms  become 
more  pronounced,  and  an  increasing  debility  ushers  in  a  usually  fatal 
ending. 

Treatment. — The  treatment  of  jivfemia  should  be  preventative. 
The  carrying  out  of  rigid  antiseptic  precautions  has  much  lessened 
the  frequency  of  pysemia.  If  areas  of  infection  are  removable,  they 
are  removed  no  matter  what  extent  of  operation  may  be  necessary. 
The  general  treatment  is  the  same  as  in  septicaemia,  with  much  less 
hope  of  recovery. 

A  consideration  of  the  infective  surgical  processes  in  connection 
with  dental  and  oral  diseases  is  of  the  utmost  moment  to  the  practi- 
tioner of  dentistry.  Nearly  all  of  the  diseases  which  the  dentist  is 
called  upon  to  treat  are  infective  from  their  inception.  Moreover,  the 
saliva,  holding  in  suspension  numerous  forms  of  bacteria,  both  sapro- 
phytic and  parasitic,  and  their  waste,  is  a  highly  infective  fluid. 

It  has  been  clearly  demonstrated  by  the  researches  of  Miller  ^  that 
many  forms  of  bacteria  found  in  specific  diseases,  and  found  inhabiting 
the  intestinal  tract,  are  more  or  less  constantly  present  in  the  human 
mouth,  and  that  the  pathway  in  many  general  infections  is  no  doubt  via 
the  oral  cavity.  A  wound  made  in  the  human  mouth  is  necessarily  an 
infected  wound.  In  the  vast  majority  of  cases  the  body  exercises  its 
protective  func^tion  in  a  phagocytosis,"  which  disposes  of  invading  bac- 

^  Micro-organisms  of  (he  Human  Mouth.  ^  Hugenschinidt,  Dental  Cosmos,  1896. 


100  INFECTIVE  INFLAMMATIONS. 

teria.    In  other  cases  it  is  beyond  question  that  this  protective  provision 
fails  and  infection  occurs. 

The  principles,  both  pathological  and  therapeutic,  which  have  been 
thus  far  expounded  are  the  general  principles  upon  which  medical  and 
surgical  practice  rests.  They  are  in  large  part  applicable  to  a  proper 
and  intelligent  practice  of  dentistry.  Dental  practice  is  daily  becom- 
ing more  and  more  recognized  as  a  special  branch  of  surgery,  the  path- 
ology, morbid  anatomy,  and  therapeutics  of  which  are  modified  by 
peculiarities  of  structure  and  position  as  in  any  other  specialty.  The 
origin,  structure,  and  function  of  dental  parts  being  special  and  distinc- 
tive, their  diseases  and  the  treatment  of  their  diseases  are  also  necessarily 
specialized.  Restating  that  in  order  to  comprehend  the  nature  of 
morbid  processes  in  a  part  it  is  necessary  to  have  a  comprehension 
of  the  embryology,  histology,  physiology,  anatomy,  and  physiological 
chemistry  of  the  part,  the  transition  is  now  naturally  to  a  discussion 
of  these  factors  in  so  far  as  their  connection  with  disease-processes  may 
be  clear. 


SECTION  II. 

ANATOMY   AND   DEVELOPMENT. 


CHAPTER   VII. 


EXT 


THE  DEVELOPMENT  AND  STRUCTURE  OF   THE  JAWS  AND 

TEETH. 

Aberrations  of  Development. 
For  a  proper  comprehension  of  many  of  the  abnormal  conditions 
fonnd  associated   with   the  jaws  and  teeth   some   famiharity  with  the 
embryology  and  an  intimate  knowledge  of  the  histology  of  the  parts 

are  necessary  preliminaries.  The  jaws  and 
teeth,  or  the  modification  of  such  structures, 
play  an  important  part  in  the  economy  of 
nearly  every  class  of  animals.  The  jaws,  de- 
signed for  the  seizing  of  prey,  represent  the 
first  structures  concerned  in  the  process  of 
nutrition.  Specialized  structures  with  which 
the  jaws  are  armed,  teeth  or  their  modifica- 
tions, add    to    this   primary  armament  and 

Fig.  44. 


EXT. 


F.F. 

Diagram  showing  relations  of 
epi-  and  hypoblast:  H.F., 
head -fold;  F.F.,  tail -fold; 
INT.,  hypoblastic  layer  of  em- 
bryo; EXT.,  epiblastic  layer ; 
PH.M.,  pharyngeal  mem- 
brane.   (Hertwig.) 

increase  its  usefulness.     The  teeth  and  jaws  are  so  intimately  associated 
that  their  embryology  must  be  studied  together. 

The  embryology  of  the  parts  concerned  with  stomatology  begins  at 

101 


Diagrammatic  outline  of  a  human  embryo  of  about  seven 
weeks,  showing  the  relations  of  the  mandibular,  mb, 
with  the  maxillary,  mx,  and  olfactory  processes,  olf.  The 
maxillary  process  is  seen  as  an  outgrowth  from  the 
base  of  the  mandibular  process.    (Allen  Thomson.) 


102  DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 

a  very  early  period — before  the  twelfth  day  the  future  mouth  may  be 
located  (His).  The  embryo,  covered  externally  by  an  epiblastic  layer,  is 
traversed  from  near  the  tail-fold  to  near  the  head-fold  by  a  tube  lined 
with  the  hypoblast.  At  the  tail-  and  head-ends  of  this  tube  the  epiblast 
and  hypoblast  are  fused  together,  forming  septa ;  the  upper  septum 
separates  the  future  mouth  from  the  future  pharynx  (PH.M.,  Fig.  43). 
The  face  and  jaws  are  outgrowths  and  attachments  to  the  primitive 
cranium,  represented  by  the  head-fold.  Before  the  fourth  week  of 
gestation  there  appear  beneath  the  head-fold  four  pairs  of  buds  grow- 
ing toward  the  median  line.  From  the  uppermost  of  these  growing 
processes  (mb.  Fig.  44)  the  lower  jaw  develops.  From  near  the  bases 
of  these  processes  buds  are  given  ofP,  which  grow  obliquely  forward  and 
upward  ;  these  processes  are  the  embryonic  upper  jaw  (mx.  Fig.  44). 
At  the  same  time  a  knob-like  process  grows  downward  from  the  end 
of  the  head-fold,  and  by  the  time  the  lower  maxillary  processes  have 
united  in  the  median  line  a  cavern  is  formed  between  these  several  pro- 
cesses, which  will  form  the  future  mouth  and  future  nasal  cavities. 
This  corresponds  with  about  the  fourth  week  of  gestation  (Fig.  45). 
The  globular  processes  growing  downward  form  the  intermaxillary 
processes  from  which  the  intermaxillary  bones  and  the  median  portion 

Fig.  45. 


Sup.  tubercle    ^     Jfe    &fe    J^.Ji^  ^'^P-  tubercle 
Lateral  tubercle  '^mUmm-^M^   ^^^^D  Lateral  tubercle 


Head  of  an  early  human  embryo,  showing  the  disposition  of  the  facial  fissures  and  of  the  superior 
and  lateral  tubercles.     (After  His.) 

of  the  lip  develop.  The  upper  maxillary  processes  grow  forward  and 
inward,  fusing  later  with  the  intermaxillary  processes  of  each  side  (Fig. 
46,  B).  Each  of  these  processes  consists  of  a  central  mass  of  mesoblastic 
tissue — i.  e.,  tissue  out  of  which  the  several  connective  tissues  of  the  jaw 
will  develop  bone,  cartilage,  muscle,  and  the  ordinary  connective  tissues. 
As  the  superior  maxillary  processes  grow  forward  to  meet  the  de- 
scending intermaxillary  processes,  each  sends  inward  a  horizontal  branch 
toward  the  median  line,  which  progressively  divides  the  large  general 


ABERRATIOXS  OF  DEVELOPMENT. 


103 


S.M.P; 


S.M.P. 


cavity  into  two  compartments  (N.C.,  nasal  cavity,  and  O.C,  oral  cavity  ; 
Fio-.  46,  A),  and  when  these  horizontal  processes  fuse  in  the  median 
line  with  the  descending  maxillary 
(intermaxillary)  processes  the  nasal 
and  oral  cavities  are  separated. 
These  fusions  occur  about  between 
the  seventh  and  ninth  weeks  of 
gestation,  the  union  at  the  forward 
end  occurring  first  and  progressing 
backward,  the  septum  being  com- 
pleted about  the  tenth  or  eleventh 
week.  Malformations  due  to  the 
non-union  of  the  parts  date,  there- 
fore, from  this  period.  Several 
types  of  deformity  arise  from  the 
non-union  or  imperfect  union  of 
these  parts.  The  horizontal  or 
palatal  processes  may  unite  with 
one  another  and  with  the  inter- 
maxillary processes,  but  their  outer 
portions  may  fail  to  fuse  upon  one  or  both  sides,  constituting  the 
condition   known   as   harelip,  shown  in  its  extreme  form  in  Fig.  47. 

Fig.  47. 


NAS. 


Complete  bilateral  fissures  (coloboma)  of  face.    (Guersant.) 

If  the  horizontal  plates  fail    to    unite  with  one  another,  an    opening 
between  the  nasal  and  oral  cavities  remains,  the  condition  being  called 


104 


DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 


cleft  palate.  The  intermaxillary  processes  may  fail  to  unite  upon 
one  or  both  sides  with  the  superior  maxillary  processes  proper,  form- 
ing clefts  which  extend  obliquely  from  the  median  line.  As  a  rule, 
the  outer  or  lip  portions  of  these  processes  also  fail  to  unite  in  this 
latter  condition,  so  that  oblique  palatal  clefts  and  harelip  are  commonly 
associated.     If  the  right  and  left  globular  or  intermaxillary  processes 

Fig.  48. 


/ 


Median  fissure  of  the  lower  lip  and  chin.    (Marshall,  after  Wofler.) 

fail  to  unite  with  one  another,  a  fissure  will  exist  in  the  median  line  of 
the  lip.  It  is  rare  that  the  right  and  left  inferior  maxillary  processes 
fail  to  unite ;  the  condition  is,  however,  occasionally  seen  (Fig.  48), 

Development  op  the  Lower  Jaw. 
The  inferior  maxillary  processes  have  united   in  the  median  line 
beneath  the  partially  developed  buds  of  the  superior  and  intermaxillary 
processes.     The  central  portions  of  the  mesoblastic  tissue  composing  the 

bodies  of  these  processes  become  transformed 
into  two  rods  of  cartilage,  which  act  as  sup- 
ports to  the  arch  during  the  period  in  which 
the  inferior  maxillary  bone  is  forming.  The 
cartilages  of  the  right  and  left  sides  do  not 
fuse  together  at  the  future  symphysis  (Hert- 
^vig)  (Fig.  49).  This  cartilage  is  but  a  tem- 
porary structure ;  it  undergoes  atrophy  at 
about  the  sixth  month  of  gestation,  and  at 
birth  but  few  fragments  are  found  near  the  symphysis.     The  end  of  the 


Fig.  49. 


M.c: 


Showing  Meckel's  cartilage  (M.C.)  in 
longitudinal  and  transverse  sec- 
tion. 


DEVELOPMENT  OF  THE  TEETH. 


105 


cartilage  in  the  base  of  the  inferior  niaxilhiry  process  becomes  the  future 
malleus  (one  of  the  bones  of  the  middle  car)  (Fig.  50).     The  portion  of 


Fig.  50. 


9'ii  Isth  gh 

Head  and  neck  of  a  human  embryo  eighteen  weeks  old,  with  tlie  visceral  skeleton  exposed.  The 
lower  jaw  is  somewhat  depressed  in  order  to  show  Meckel's  cartilage,  which  extends  to  the 
malleus.  The  tympanic  membrane  is  removed  and  the  annulus  tympanicus  is  visible,  ha, 
malleus,  which  passes  uninterruptedly  into  Meckel's  cartilage,  mk ;  uk,  bony  lower  jaw 
(dentale),  with  its  condyloid  process  articulating  with  the  temporal  bone ;  am,  incus ;  st, 
stapes ;  pr,  annulus  tympanicus  ;  grf,  processus  styloideus  ;  Uth,  ligamentum  stylohyoideum  ; 
kh,  lesser  cornu  of  the  hyoid  bone ;  fjh,  its  greater  cornu.    Magnified.    (After  KoUiker.) 

the  cartilage  running  from  the  malleus  to  the  formed  bony  lower  jaw 
becomes  transformed  into  the  internal  lateral  ligament  of  the  inferior 
maxilla  (Hertwig), 

Development  of  the  Teeth. 
The  first  evidences  of  tooth-formation  are  seen  at  about  the  sixth 
week  of  gestation,  at  a  period  when  the  superior  and  inferior  maxillary 
processes  are  but  ill-defined  masses  of  mesoblastic  tissue  surrounded  on  all 
sides  by  epiblastic  tissue.  Before  the  union  of  the  processes  which  are  to 
separate  the  nasal  from  the  oral  cavity  and  which  form  the  future  palate, 
is  complete,  the  first  evidences  of  tooth-formation  may  be  observed. 
It  is  to  be  borne  in  mind  that  during  the  entire  period  of  tooth-forma- 
tion other  formative  changes  are  in  operation,  out  of  which  arise  all  of 
the  parts  associated  with  the  teeth.  A  transverse  section  of  the  lower 
jaw  at  this  period  will  exhibit  an  ellipsoidal  surface  in  which  there  can 
be  plainly  seen  a  mass  of  indifferent  mesoblastic  tissue,  surrounded  by 
epiblastic  tissue,  except  at  the  middle,  where  it  is  reflected  over  a  pear- 
shaped  structure — the  future  tongue  (Fig.  51).     Within  the  substance  of 


106 


DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 


the  mesoblastic  tissue  are  seen  two  elliptical  areas,  the  sections  of  Meckel's 
cartilage.  If  the  sections  are  made  near  the  median  line,  these  oval 
areas  will  be  close  together ;  if  much  farther  back,  they  will  be  widely 
separated.  On  the  upper  surface  of  the  jaw,  upward  and  outward  from 
Meckel's  cartilage,  the  epithelium  is  seen  to  be  much  thicker  at  a  point 
on  each  side  than  it  is  over  other  parts  ;  the  free  surface  of  the  epithe- 
lium at  this  point  rises  above  the  general  surface,  and  where  the  epithe- 
lium is  in  contact  with  the  mesoblastic  tissue  it  sinks  below  the  general 


Fig.  51. 


A  section  through  the  developing  jaws  at  about  the  seventh  or  eighth  week:  N.  P.,  nasal 
process  ;  T.,  tongue  ;  M.  C,  Meckel's  cartilage  ;  T.  B.,  tooth-bands. 

surface  (Fig.  51,  T.B.).  Sections  made  from  before  backward  show  that 
this  dipping  in  and  elevation  of  the  epithelium  extend  along  the  arch  of 
the  jaw,  so  that  if  viewed  from  above  it  presents  a  horseshoe-shaped  ridge 
occupying  the  summit  of  the  embryonic  jaw.  The  elevation  is  greatest 
in  front,  thinning  gradually  toward  the  heels  of  the  horseshoe.  This  is 
the  primary  dental  ridge.  Older  microscopists,  notably  Goodsir,  obtained 
specimens  from  which  the  epithelium  had  been  removed,  and  hence  the 
depression  made  by  the  base  of  the  epithelial  growth  in  the  mesoblastic 
tissue  gave  the  appearance  of  a  groove,  called  by  Goodsir  the  primitive 
dental  groove.  Sections  made  of  older  jaws  exhibit  the  gradual  evo- 
lution of  the  structures  of  the  jaw. 


DEVELOPMENT  OF  THE  TEETH. 


107 


The  local  overgrowth  of  epithelium  proceeds  until  the  ridge  is  well 

Fig  52 


Fig.  53. 


Longitudinal  transverse  section  of  the  inferior  maxilla  of  a  porcine  embryo:  6,  band,  solid  at 
anterior  portion,  but  divided  posteriorly  into  band  and  lamina.    (3  cm.  X40.)    (Sudduth.) 

marked,  and  the  lower  epithelium — /.  e.,  the  germinal  layer — is  seen  to 
sink  deeper  and  deeper  into  the  meso- 
blastic  tissue,  forming  a  continuous 
horseshoe-shaped  band  of  epithelium ; 
the  epithelium  in  this  condition  is 
called  a  band  (Fig.  52,  b).  At  a  later 
stage  the  rounded  base  of  the  band 
becomes  flattened;  this  base  is  then 
termed  a  lamina — the  dental  lamina. 
From  the  inner  angle  of  this  lamina 
ten  buds  are  given  off,  each  corre- 
sponding with  a  future  deciduous 
tooth  (Fig.  53,  c).  These  ten  buds, 
or,  as  they  are  called,  dental  cords, 
grow  inward  into  the  mesoblastic 
tissues,  the  anterior  preceding  in 
growth  the  posterior  cords.  Each 
developing  cord  appears  soon  to 
meet  with  an  outlined  resistance,  corresponding  roughly  with  the  shapes 


Vertical  section  through  band  from  jaw  of 
porcine  embryo :  ep,  epithelium  ;  6,  band  : 
c,  cord  ;  ct,  connective  tissue.  (3k  cm.  X  60.) 
(Sudduth.) 


108 


DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 


of  the  several  teeth.  It  might  be  said  with  perhaps  equal  propriety 
that  the  base  of  the  cord  assumes  these  shapes,  as  the  origin  of  the 
assumption  of  the  typical  forms  is  unknown.     The  mesoblastic  tissue 


Fig.  54. 


Vertical  section  through  band  and  cord  of  3i  cm.  porcine  embryo  X  60:  ep,  epithelium  with  infant 
layer  (il) ;  6,  band ;  c,  pear-shaped  cord ;  dp,  dental  papilla ;  ct,  connective  tissue.  In  this  cut 
the  walls  of  the  cord  are  shown  very  plainly  to  be  a  continuation  of  the  infant  layer  of  the 
epithelium.    (Sudduth.) 

is  observed  to  be  condensed,  to  be  faintly  differentiated,  from  the  indif- 
ferent mesoblastic  tissue ;  this  condensed  area  will  ultimately  form  the 
dental  pulp  (Fig.  54). 

As  the  ingrowth  of  the  epithelium  proceeds,  definite  changes  are  seen 
to  occur  in  the  epithelial  mass,  which  will  later  be  described  in  detail. 
This  epithelial  mass  is  the  structure  through  which  the  enamel  of  the 
teeth  will  be  formed,  and  hence  is  called  the  enamel-organ.  As  it 
grows  bodily  inward,  changes  are  observed  in  the  tissues  about  it ;  the 
indifferent  mass  of  mesoblastic  tissue,  constantly  increasing  in  size,  is 
seen  to  undergo  differentiations  at  isolated  points  ;  bone-forming  cells — 
osteoblasts — make  their  appearance  and  form  bone  without  antecedent 
cartilage  and  without  evidence  of  a  periosteum  ;  this  has  been  called 
interstitial  bone-formation  ^  (Fig.  55).  Condensations  of  tissue  occur 
about  the  outside  of  these  several  bone-islands,  an  embryo  periosteum  ; 
the  development  of  the  bony  jaw  is  now  in  progress.  It  will  be  ob- 
served that  Meckel's  cartilage  is  not  included  in  the  area  marked  off  as 
the  bony  jaw  (Fig.  55). 

Outside  the  embryo  periosteum  evidences  of  the  future  muscles  of 
the  jaws  appear.     As  the  growth  of  the  enamel-organ  continues,  and  as 

^  Sudduth,  in  American  System  of  Dentistry. 


DEVELOPMENT  OF  THE  ENAMEL. 


109 


it  assumes  upon  its  inner  surface  the  form  of  the  future  tooth,  the  con- 
nective tissue  surrounding  it  acquires  the  character  of  a  thick  fibro- 
membrane,  which  Uiter  encloses  the  entire  developing  tooth-pulp  and 
enamel-organ.  These  structures,  out  of  which  all  of  the  dental  tissues, 
with  the  exception  of  the  nerves,  will  be  evolved,  are  now  collectively 
called  the  dental  follicle.     The  growth  of  bone  continues,  so  that  the 


mv.  ^P- 

Vertical  transverse  section  of  jaw  of  porcine  emhryo,  showing  differentiation  of  periosteum  :  pp, 
periosteum  of  either  jaw  ;  c.ct,  follicular  wall,  appearing  as  a  continuation  of  the  periosteum  ;  6, 
band ;  eo,  enamel  organs  for  premolars ;  ep,  epithelium ;  db,  developing  bone ;  mc,  Meckel's 
cartilage.    (b\  cm.  X  25.)     (Sudduth.) 

ten  follicles  lie  now  in  a  gutter  of  bone,  the  developing  maxilla.  Before 
the  enamel-organs  assume  their  typical  forms  the  cords  from  which  each 
arose  are  each  seen  to  give  off  a  bud,  which  grows  downward  and  inward  ; 
as  regards  the  first  cords,  they  are  cords  out  of  which  the  enamel- 
organs  of  the  permanent  teeth  will  be  developed.  The  cord  of  each 
temporary  tooth  gives  off  the  cord  of  its  permanent  successor.  Behind 
the  cord  for  the  second  deciduous  molars,  and  some  writers  have  said 
directly  from  it,  a  cord  arises  for  the  first  molar  of  the  permanent  den- 
ture ;  this  occurs  before  the  sixteenth  week.  At  about  this  period  the 
epithelial  bands  connecting  the  enamel-organs  with  the  surface  epithe- 
lium of  the  mouth  break  up  into  whorls  and  connection  between  the 
developing  teeth    and  mucous  membrane  is  lost. 

Development  op  the  Enamel. 

Each  of  the  dental  tissues  is  developed  after  a  distinctive  manner, 
and  the  process  requires  close  observation  with  very  high  microscopic 
powers  to  make  out  all  of  the  details.     Although  in  point  of  time  the 


r.  ct. 


110 


DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 


first  layer  of  dentin  is  cleiwsited  before  the  first  layer  of  enamel,  the 
changes  and  evolutions  M^iich  occur  in  the  enamel-organ  may  be  made 
out  before  the  details  of  the  structure  of  the  dental  pulj)  become  appar- 
ent ;  for  this  reason  the  development  of  enamel  is  first  studied. 


Fig.  56, 


Vertical  transverse  section  of  jaw  of  porcine  embryo,  injected :  ep,  epithelium,  with  (il)  infant 
layer  ;  a,  layer  of  amelob lasts  ;  o,  layer  of  odontoblasts  ;  cp,  cord  for  permanent  tooth  :  ot,  outer 
tunic  ;  it,  inner  tunic;  sr,  stellate  reticulum;  wh.  ep.,  whorls  of  epithelium  formed  from  outer 
tunic  and  stellate  reticulum  ;  d,  dentin ;  dp,  dentinal  pulp ;  v,  bloodvessels  of  pulp ;  ct,  con- 
nective tissue  ;  c.  ct,  follicular  wall ;  p,  periosteum  ;  sp,  space.     (10  cm.  X  60.)     (Sudduth.) 

It  will  be  observed  that  the  indipping  of  epithelium  into  the  raeso- 
blast  is  an  indipping  of  the  deepest  or  germinal  layer  of  epithelial  cells. 
It  is  noted  at  this  period  that  while  the  epiblastic  tissue  is  clearly 


DEVELOPMENT  OF  THE  ENAMEL. 


Ill 


marked  off  from  the  mesoblastic,  no  such  structure  as  a  basement- 
membrane  exists.  As  the  dental  cord  increases  in  depth  it  increases 
in  breadth,  the  germinal  layers  remaining  distinct ;  older  cells  make 
their  appearance  between  the  layers.  Following  the  formation  of 
the  cords  and  their  evolution  into  the  enamel-organs,  it  is  seen  that 
the  organ  becomes  first  conical,  the  sides  and  base  of  the  cone  Ijeing 
formed  of  germinal  ei)ithelium  ;  a  depression  constantly  increasing  in 
depth  forms  in  the  base  of  the  cone,  until  finally  the  enamel-organ  is 
seen  to  consist  of  a  double  layer  of  germinal  epithelium,  the  layers 
being  separated   by  epithelial  cells   of    an  older  type,  which  undergo 

Fig.  57. 


Section  of  a  developing  cuspid  (human)  at  about  the  sixth  month :  4,  ameloblasts;  B,  enamel; 
C,  dentin  ;  D,  odontoblasts;  E,  stratum  intermedium  ;  jF,  stellate  reticulum  ;  O,  follicular  wall. 


a  remarkable  increase  in  size.  At  this  time,  or  a  little  later,  blood- 
vessels make  their  appearance  in  the  condensed  mesoblastic  tissues 
covered  by  the  enamel-organ.  Springing  from  the  base  of  this  con- 
densed mass,  fibrous  tissue  makes  its  appearance,  extending  up  and 
along  the  sides  of  the  enamel-organ  ;  this  is  recognized  as  the  wall  of 
the  dental  follicle  (Fig.  56,  c.d.).  Between  the  fourth  and  sixth  months 
of  gestation  the  differentiation  of  the  parts  of  the  enamel-organ  are  evi- 
dent. The  cells  of  the  inner  germinal  layer  of  epithelium,  that  next  to 
the  mesoblastic  tissue,  are  seen  to  assume  a  prismatic  form,  the  change 
being  most  pronounced  above  the  apex  of  the  future  pulp.     The  outer 


112 


DEVELOPMENT  OF  THE  JAWS  AND  TEETH. 


epithelial  layer  for  the  present  is  of  cuboidal  cells  ;  between  these  two 
layers  two  types  of  epithelial  cells  are  seen.  The  cells  occupying  the 
greater  mass  of  the  enamel-organ  are  greatly  distended ;  owing  to  the 
appearance  of  these  cells  when  seen  in  section  (Fig.  57,  F)  the  structure 
has  been  called  the  stellate  reticulum,  or  star-like  network.  It  was  at 
one  time  thought  that  the  cells  of  this  portion  of  the  enamel-organ  were 
devoid  of  cell-contents,  the  distention  being  caused  by  the  accumulation 
of  fluid  between  the  cells.  It  has  been  lately  shown  ^  that  the  cells  them- 
selves are  enormously  distended  or  enlarged  (Figs.  57,  58).     The  layer 

Fig.  58. 


/' 


S  r  .    ■'  JW*  It  '^        ^ 


Section  of  developing  tooth  of  an  embryo  calf  u  ^ttlLite  reticulum  of  enamel-organ ;  ft,  stratum 
intermedium ;  r,  ameloblasts  ;  d,  dentin  ;  e,  odontoblasts ;  /,  bloodvessel— corpuscles  in  situ. 
X  275.    (Williams.) 

of  cells  next  to  the  pulp  which  have  assumed  the  prismatic  form  are  those 
through  which  enamel-building  will  be  accomplished,  hence  they  are 
called  ameloblasts  or  enamel-builders.  Between  the  ameloblasts  and 
the  stellate  reticulum  proper,  the  epithelial  cells  are  of  smaller  size  than 
those  of  the  latter,  are  distinct,  and  are  more  firm.  This  layer  is  called, 
.    '  J.  L.  Williams,  Dental  Cosmos,  1896. 


DEVELOPMENT  OF  THE  ENAMEL.  113 

from  its  position,  the  stratum  interiiuHliiim.  The  fibrous  tissue  form- 
ino-  the  follicular  wall  is  observed  in  close  relation  with  the  outer  epi- 
thelial layer  of  the  enamel-organ.  The  structures  necessary  to  the 
formation  of  enamel  are  now  diiferentiated,  but  before  this  process  can 
be  comprehended  a  brief  survey  of  the  physiological  chemistry  of  the 
operation  is  advisable. 

The  enamel  of  the  teeth,  by  present  methods  of  chemical  analysis, 
is  found  to  be  composed  in  large  part  of  calcium  salts,  the  phosphate 
and  carbonate ;  and  yet  in  its  structure  and  texture  it  in  no  way  re- 
sembles the  ordinary  crystallized  forms  of  these  mineral  salts,  so  that 
the  formation  of  enamel  is  not  merely  the  deposition  and  crystallization 
of  calcium  phosphate  and  carbonate.  It  is  beyond  question  that  enamel 
is  a  compound  of  organic  origin,  and  the  nature  of  its  substance  must 
be  sought  for  among  the  organic  compounds. 

The  experiments  of  Harting,  Rainey,  and  Ord,^  have  shown  a 
reaction  which  no  doubt  has  a  direct  bearing  upon  the  formation  of  all 
calcified  tissues.  If  to  an  albuminous  solution  a  solution  of  a  calcium 
salt  be  added,  the  calcium  enters  into  chemical  combination  with  the 
albumin,  forming  a  substance  indefinitely  known  as  albuminate  of  cal- 
cium, and  called  by  its  discoverer  calco-globulin.  If  calcium  carbonate 
be  formed  in  a  solution  of  albumin,  the  above  combination  occurs,  making 
definite  structural  forms,  minute  laminated  spheres,  which  are  called 
calco-spherites ;  these  spheres  coalesce  and  form  laminated  masses — 
i.e.,  form  in  layers.  When  exposed  to  the  action  of  dilute  acids  these 
spherites  are  more  resistant  than  the  crystallized  salts ;  moreover,  after 
the  action  of  the  acid  the  form  of  the  spherite  remains.  This  chemical 
fact,  the  union  of  crystalloidal  with  colloidal  substances,  is,  no  doubt, 
of  wide  significance  in  general  and  special  pathology,  for  it  is  extremely 
probable  that  the  formation  of  all  pathological  concretions  is  an  expres- 
sion of  some  such  reaction.  The  evidence  is  strong  that  calcium  albu- 
minate is  the  basis  of  all  of  the  calcic  tissues ;  but  precisely  where 
its  formation  occurs  in  enamel-formation  is  unknown  ;  presumably,  it 
occurs  or  is  completed  in  the  enamel-forming  cells. 

Williams  has  shown,-  by  selective  staining,  that  prior  to  and  during 
enamel-formation  the  ameloblasts  are  separated  from  the  developing 
enamel  upon  one  side  and  from  the  stratum  intermedium  upon  the 
other  side  by  what  appear  to  be  membranes,  so  that  any  future  genera- 
tion of  enamel-cells,  if  such  occur,  must  be  from  the  ameloblasts  them- 
selves. Moreover,  the  cells  of  the  stratum  intermedium  are  not  of 
the  germinal  type.     Andrews^  calls  attention  to  the  fact  that  if  a  sec- 

'  E..  R.  Andrews,  American  Text-hook  of  Operative  Dentistry. 

^  Dental  Coi^mos,  1896,  p.  107  et  seq. 

*  American  Text-book  of  Operative  Dentistry,  1897. 


114 


DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 


tion  of  an  enamel-organ  at  this  period  be  placed  under  a  cover-glass 
and  a  diluted  mineral  acid  be  permitted  to  run  under  the  glass,  bubbles 
of  gas  (carbon  dioxid),  are  disengaged,  showing  the  presence  of  calcium 
salts  in  the  structures.  The  bubbles  form  in  the  stellate  reticulum, 
in  the  ameloblasts,  in  the  structure  between  the  ameloblasts  and  the 
first-formed  layer  of  dentin,  and  in  the  latter  tissue. 

In  the  ameloblasts,  having  large,  well-marked  nuclei  at  their  distal 


Fig.  59. 


Section  of  developing  tooth  of  an  embryo  calf:  a,  b,  nuclei  of  reticulum  of  enamel-organ,  showing 
spongiose  character ;  c,  outer  ameloblastic  membrane  ;  d,  inner  ameloblastic  membrane  ;  e,  f, 
enamel-globules  faintly  showing  nuclear  network.    X  1000.    (Williams.) 

portions  two  distinct  cell-contents  are  seen  :  one,  glistening  droplets 
of  various  sizes,  which  coalesce,  becoming  larger  as  they  approach  the 
proximal  end  of  the  ameloblasts,  out  of  which  they  are  extruded  against 
the  forming  dentin.     In  addition  to  these  droplets  the  ameloblasts  are 


DEVELOPMENT  OF  THE  ENAMEL. 


115 


seen  to  contain  one  or  more  globular  bodies,  all  of  like  size,  lying 
between  the  nucleus  and  the  proximal  end  of  the  cell.  These  globules 
are  connected  with  one  anotlier  by  phismic  strings.  Into  the  mass 
formed  by  the  fusing  together  of  the  droplets  first  extruded  from  the 
ameloblasts,  these  uniform-sized  globules  are  deposited.  The  first-named 
material,  nominally  (^alco-globulin,  is  a  cement-substance  which  flows 
around  and  about  the  globules  and  their  processes.  The  globules,  from 
mutual  pressure,  assume  naturally  a  prismatic  form.  The  globular 
bodies  are  called  by  Williams  enamel-globules.  The  small  droplets 
out  of  which  the  cement-substance  is  formed  are  found  also  in  the 
stratum  intermedium ;  differential  staining  demonstrates  this.  The 
enamel-globules  stain  differently,  are  of  one  size,  and  are  only  noted 
between  the  nucleus  and  the  proximal  end  of  the  cell.  AVilliams  infers 
that  they  arise  by  a  process  of  mitosis  or  cell-multiplication  from  the 
nucleus  itself,  a  most  rational  conclusion.  As  soon  as  the  first  layers 
of  enamel  have  formed  a  notable  change  is  seen  to  occur  in  the 
enamel-organ  ;  the  stellate  reticulum  disappears  over  the  forming 
enamel.  The  calcic  material  stored  in  its  cells  has  been  exhausted  in 
forming  the  first  layer  of  enamel ;  the  succeeding  enamel  has  a  different 

Fig,  go. 


Section  of  incisor  of  rat :  n,  capillary  loops  torn  out  of  secreting  papillae ;  6,  secreting  papillae  after 
removal  of  capillary  loops ;  c,  ameloblasts ;  d,  enamel:  e,  dentin.    X  80.    (Williams.) 

source  of  formative  material.  The  stellate  reticulum  atrophies  and  the 
outer  boundary  wall  of  the  enamel-organ  comes  in  apposition  with  the 
stratum  intermedium.  Williams  observed  in  the  enamel-organs  of  rodents 
(Fig.  60)  that  the  cells  of  the  stratum  intermedium  become  arranged 
over  loops  of  vessels  from  the  vascular  coat,  so  that  papillse  are  formed. 
He  infers  that  a  similar  arrangement  occurs  in  the  enamel-organ  of  man  ; 
and  that  the  function  of  the  papillary  structure  is  the  selection  from  the 
blood-plasma  of  material  to  be  passed  into  the  ameloblasts  out  of  which 


116 


DEVELOPMENT  OF  THE  JAWS  AND  TEETH. 


the  enamel  is  formed.  The  deposition  of  cementing-substance  and 
connected  globules  continues,  and  the  enamel  increases  in  thickness 
from  the  dentin  outward  (Fig.  61).     The  enamel  over  the  tips  of  the 


Fig.  61. 


Mode  of  enamel-deposition:  A,  formed  enamel;  B,  ameloblasts;  C,  secreting  papillae  of  stratum 
intermedium :  D,  bloodvessels  in  external  fibrous  coat  and  to  secreting  papillae ;  E,  enamel- 
globules  with  connecting  plasmic  strings ;  F,  nuclei  of  ameloblasts  ;  O,  odontoblasts ;  H,  blood- 
supply  to  odontoblastic  layer ;  /,  unformed  dentin  ;  /,  formed  dentin.  Semi-diagrammatic. 
(After  Williams.) 

teeth  is  first  formed,  and  as  this  portion  of  enamel  increases  in  thickness 
successive  portions  of  the  ameloblastic  layer  acquire  formative  function ; 
the  covering  stellate  reticulum  gradually  disappears,  until  by  the  time 
the  neck  enamel  begins  to  form  no  vestiges  of  the  stellate  reticulum 
remain.  This  deposition  of  substance  continues  until  the  crown  of  the 
tooth  has  its  normal  form,  the  ameloblasts  appearing  to  undergo  partial 
calcification  themselves,  resulting  in  the  formation  of  a  continuous  sheet 
covering  the  enamel,  and  constituting,  at  least  in  part,  Nasmyth's 
membrane. 

Formation  of  Dentin. 

Prior  to  the  appearance  of  any  calcic  tissues  in  the  teeth,  it  is  noted 
that  upon  the  periphery  of  the  developing  pulp,  notably  in  the  positions 
of  the  future  cusps,  a  layer  of  cells  becomes  differentiated  from  the  in- 


FORMATION  OF  CFMENTUM  AND  ROOTS  OF  TEETH. 


117 


different  mesoblastic  tissues  of  the  pulp  ;  these  cells  assume  an  arrange- 
ment like  that  of  cylindrical  epithelium,  but  are  not  in  lateral  contact 
with  one  another.  Beneath  this  layer  of  cells,  called  from  their 
function  the  odontoblasts  {pdoiis  and  blastos),  a  capillary  network  is 
formed,  the  capillaries  extending  by  loops  into  the  odontoblastic  layer 
(Fig.  61).  Before  any  deposition  of  enamel  occurs  it  is  seen  that  the 
odontoblasts  exude  and  extrude  from  their  distal  ends  masses  of  calco- 
S})herites.  As  this  deposition  proceeds  the  odontoblasts  recede,  each 
cell  leaving  one  or  more  branched  processes  in  the  dentin-deposit. 
The  deposition  continues,  the  dentinal  pulp  constantly  decreasing  in 
volume  as  the  dentinal  deposit  increases  in  amount.  When  it  is 
remembered  that  the  deposit  of  dentin  begins  before  that  of  the  enamel, 
it  explains  how  the  processes  from  the  odontoblasts  may  be  found  in 
the  enamel  in  exceptional  cases ;  the  processes  may  grow  outward  be- 
tween the  ameloblasts,  and  a  deposit  of  enamel  occur  about  them.  This 
condition,  normal  in  the  teeth  of  some  animals,  is  occasionally  seen  in 
the  teeth  of  man.^ 


Formation  op  Cementum  and  Roots  of  Teeth. 

The  deposition  of  cementum  begins  after  the  formation  of  enamel  is 
practically  complete.     The  formation  of  cementum  is  identical  with  the 

Fig.  62. 


A,  developing  bone ;  B,  tissue  reflected  from  follicular  wall  and  forming  alveolar  periosteum ; 
C,  follicular  wall ;  D,  vessels  and  nerves  ;  E,  epithelium  of  gum. 

subperiosteal  formation  of  bone.     By  tlie  time  that  enamel-formation 
is  complete,  or  nearly  so,  the  greater  bulk  of  the  crown  dentin  has  been 

^  Williams,  Proc.  Odontolorjkul  Society  of  New  York,  1896. 


118  DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 

formed  and  the  dental  pulp  is  contracted  from  above,  less  upon  the 
sides,  and  is  widely  open  beneath.  The  developing  teeth  at  this  stage 
rest  in  a  gutter  of  bone,  which  at  present  makes  up  the  greater  bulk  of 
the  inferior  maxilla.  The  bases  of  the  teeth  are  not  far  removed  from 
the  canal  containing  the  nutrient  vessels  and  nerves  ;  the  inferior  dental 
canal — that  is,  the  neck  of  the  tooth — is  in  the  position  which  will  be 
occupied  by  the  apex  of  the  root  after  the  tooth  is  fully  formed.  It  is 
evident,  therefore,  that  the  growth  of  the  root  of  the  tooth  must  mean 
its  extension  upward,  the  only  direction  in  which  it  is  free  to  move,  it 
being  observed  that  the  gutter  of  bone  in  which  the  teeth  lie  is  not  com- 
jjletely  closed  above  (Fig.  62).  It  is  asserted  by  Hertwig  ^  that  the  ex- 
tremity of  the  enamel-organ  grows  dowuAvard  beyond  the  crown  of  the 
tooth,  so  that  the  following  relationship  is  established :  a  layer  of 
odontoblasts  is  found  upon  one  side  of  this  epithelial  layer  ;  upon  its 
other  side  the  follicular  wall  comes  in  close  apposition.  The  epithelial 
sheath  atrophies,  and  is  probably  the  source  of  the  epithelial  whorls 
found  in  the  pericementum.  The  deposition  of  root-dentin  begins 
before  any  cementum  is  formed,  the  first  deposited  portions  of  dentinal 
matter  being  frequently  marked  by  faulty  organization,  forming  the 
line  of  imperfect  calcification  known  as  the  stratum  granulosum.  The 
fibrovascular  covering  of  this  portion  of  dentin  becomes  a  modified  peri- 
osteum ;  a  layer  of  osteogenetic  cells  appears  upon  the  portion  next  to 
the  dentin.  These  cells,  from  their  function,  are  called  cementoblasts  ; 
they  lie  as  flattened  cells,  between  which  large  fibres  from  the  fibro- 
vascular portions  of  this  tissue  pass.  The  fibrovascular  osteogenetic 
tissue  spreads  over  the  developing  bone  about  the  forming  tooth,  and  is 
thus  both  alveolar  periosteum  and  pericementum.  The  crown  of  the 
tooth  is  thrust  forward  as  the  root  develops,  and  no  doubt  the  gradual 
growth  of  the  bone  about  the  teeth  is  also  a  factor  in  the  movement  of 
the  tooth.  The  remainder  of  the  process  will  be  discussed  under  the 
head  of  dentition. 

By  the  time  the  crowns  of  the  teeth  have  made  their  appearance 
through  the  gum  the  root-formation  is  still  incomplete.  As  the  crown 
of  the  tooth  advances  the  bone  which  overlays  the  crown  undergoes 
sufficient  absorption  to  permit  the  passage  of  the  crown,  the  bone  being 
at  other  parts  separated  from  the  tooth  and  its  partially  formed  root  by 
the  thick  layer  of  connective  tissue,  forming  pericementum  and  alveolar 
periosteum.  Deposition  of  dentin  and  cementum  continues  until  the 
root-form  is  complete  ;  after  eruption,  bone-formation  about  the  tooth 
reduces  the  thickness  of  the  pericementum  and  sheaths  the  roots  of  the 
teeth  in  a  bony  covering. 

The  development  of  the  permanent  teeth  follows  a  similar  course  ; 
^  Rose,  Dental  Cosmofs,  1893. 


LATER  DEVELOPMENT  OF  THE  MAXILLM.  119 

beginning  with  the  follicle  of  the  first  permanent  molar,  which  is  dif- 
ferentiated between  the  fourth  and  fifth  months  of  gestation,  situated 
behind    the    developing    deciduous    second    molar.     The  ^^^  gg 

enamel-organ  of  the  second  permanent  molar  arises  from 
the  cord  of  the  first,  between  the  seventh  and  eighth 
months  of  gestation  ;  the  enamel-organ  of  the  third  perma- 
nent molar,  arising  in  its  turn  from  the  cord  of  the 
second  molar,  does  not  appear  until  about  the  third  year. 
The  cords  for  the  other  permanent  teeth — incisors,  cus- 
pids, and  bicuspids — appear  as  offshoots  from  the  cords 
of  the  temporary  teeth  which  they  are  to  succeed,  at 
from  the  fourth  to  the  fifth   month.      At  the  time  of 

,         ,    .         Showing  the  re- 
birth the  follicles  of  these  teeth  are  complete,  and  calci-       lation  of  per- 

fication  begins  shortly  thereafter.     The  development  of        Sn^cieM^'ufe 

the  temporary  teeth  is  accomplished  in  a  period  averag-       rootofthetem- 

ing  about  three  years  ;  that  of  the  permanent  teeth  re-       porary 

quires  for  the  first  formed  tooth  about  seven  years,  and  for  the  last 

formed  about  fourteen  years. 

The  developing  permanent  teeth  are  situated  behind  and  beneath  the 

temporary  teeth  (Fig.  63),  the  development  of  bone  about  the  follicles  of 

the  permanent  teeth  enclosing  each  of  them  in  a  distinct  pocket  of  its  own, 

a  bony  lamina  existing  between  each  follicle  and  the  tooth-root  adjacent. 

It  is  to  be  noted  that  the  developing  permanent  teeth  are  separated 

from  the  inferior  dental  canal  by  a  lamina  of  bone ;  the  canal,  it  will  be 

seen,  has  in  the  child  at  birth  but  comparatively  little  thickness  of 

covering-bone  beneath  it — i.  e,,  the  body  of  the  bone  is  very  slight. 

Later  Development  of  the  Maxilla. 

The  maxillffi  have  developed  during  the  period  included  in  the 
foregoing  description  mainly  as  tooth-carriers  and  supports ;  the 
maxillae  proper  have  not  developed  to  a  corresponding  degree.  The 
body  and  rami  of  the  lower  jaw  represent  only  the  lesser  portion  of  the 
entire  maxillae ;  the  body  of  the  upper  jaw  is  at  all  aspects  but  a 
diminutive  of  the  mature  jaw. 

At  the  time  of  birth  Meckel's  cartilage  has  disappeared,  but  a  few 
fragments  are  left  about  the  symphysis.  The  site  of  this  anatomical 
scaifolding  is  represented  by  the  mylohyoid  groove,  a  groove  beneath  the 
inferior  dental  canal,  which  lodges  the  mylohyoid  branch  of  the  inferior 
maxillary  nerve.  As  stated,  the  alveolar  portion  of  the  jaw  forms  its 
major  and  most  prominent  part.  The  body  and  rami  of  the  bone  are  at 
a  very  immature  stage.  The  body  of  the  bone,  that  beneath  the  alveolar 
portion,  is  a  comparatively  small  and  thin  shell  of  bone,  something 
more  than  sufficient  to  accommodate  freely  the  inferior  dental  artery, 


120 


DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 


nerves,  and  veins  which  it  encloses.     The  rami  of  the  jaw  are  very 
short.     The  coronoid  process  arises  to  but  a  small  height,  and  almost 

Fig.  64. 


Representing  a  jaw  of  a  nine  months'  foetus,  superimposed  on  an  adult's  jaw,  to  show  in  what 
directions  increase  has  taken  place.    (Tomes.) 

immediately  behind  the  covering  of  the  second  deciduous  molar  follicle ; 
the  condyloid  process  is  at  about  the  same  height,  but  little  above  the 

Fig.  65. 


Showing  the  relative  sizes  of  jaws  at  the  age  of  two  years  and  in  the  adult. 

level  of  the  gum-summit,  there  is  not  that  sharp  distinction  between 
ramus  and  body  seen  at  later  stages. 


DEVELOPMENT  OF  THE   UPPER  JAW.  121 

If  the  inferior  maxillse  of  an  infant  at  the  time  of  first  dentition  be 
compared  with  that  of  an  adult,  it  will  be  seen  that  the  radii  of  the  dental 
arches  in  both  jaws  are  nearly  alike.  The  comparison  may  be  more 
readily  made  if  the  two  jaws  be  compared  at  the  completion  of  the 
primary  dentition  (Figs.  64  and  65).  It  will  be  observed  that  the  body 
of  the  mature  jaw  projects  very  much  at  the  anterior  and  lateral  aspects 
of  the  jaw,  but  the  greatest  amount  of  growth  is  backward  and  upward  ; 
these  are,  therefore,  the  directions  in  which  the  greatest  growth  occurs. 
The  coronoid  process,  which  at  two  years  is  but  little  behind  the  second 
temporary  molar,  recedes,  until  at  about  the  age  of  seventeen  years  the 
space  between  the  ramus  and  the  former  position  of  the  second  deciduous 
molar  is  sufficient  to  accommodate  the  three  largest  teeth  of  the  dental 
series. 

The  depth  of  the  jaw,  the  portion  of  the  jaw  lying  beneath  the  men- 
tal foramen,  is  nearly  acquired  by  the  seventh  year ;  the  height  of  the 
jaw  (the  portion  above)  is  not  acquired  until  some  time  after  the  full 
eruption  of  the  permanent  teeth.  From  the  time  of  birth,  the  anterior 
portion  of  the  body  of  the  jaw — that  in  front  of  the  mental  foramen — 
dev^elops,  as  shown  in  Fig.  64,  by  additions  to  its  front  wall.  The  not- 
able increase  is  backward  and  by  an  upward  movement  of  the  rami. 
The  direction  of  the  movement  of  the  condyle  during  development  is 
obliquely  backward  and  upward.  "  The  condyle  occupies  during  devel- 
opment of  the  jaw,  successively,  every  point  of  the  internal  oblique 
line." ' 

"  The  course  of  the  coronoid  process  is  to  be  seen  in  the  external  ob- 
lique line."  ^  The  formation  of  the  condyloid  portion  of  the  bone  is 
largely  cartilaginous,  the  formation  of  the  other  growing  portions  of 
the  bone  being  almost  entirely  subperiosteal.  There  is  a  complex  ac- 
companiment of  resorption  with  deposition,  in  the  formation  of  the  rami 
of  the  lower  jaw.  The  amount  of  bone  deposited  during  the  growth  of 
the  ramus  of  the  jaw  would  represent  a  quadrangular  block  the  thickness 
of  the  condyle,  and  extending  backward  from  the  posterior  surface  of 
the  second  bicuspid  to  the  back  edge  of  the  jaw,  and  from  the  alveo- 
lar border  to  the  height  of  the  condyle  at  maturity  ;  but  as  the  depo- 
sition of  bone  occurs  backward  and  upward,  the  redundant  deposit 
undergoes  an  absorption  which  carves  the  bone  into  its  typical  form. 

Development  of  the  Upper  Jaw. 

Observations  as  to  the  exact  mode  of  development  of  the  upper  jaw 
are  not  so  complete  as  those  relating  to  the  lower  jaw.  At  the  begin- 
ning of  tooth-formation  in  the  upper  jaw  the  junctions  between  the 
right  and  left  palatal  processes,  and  of  the  intermaxillary  processes 

^  C.  Tomes.  ^  Ibid. 


122  DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 

with  both,  have  not  occurred.  In  the  intermaxillary  portions  the  fol- 
licles for  the  incisor  teeth  are  formed.  After  the  junction  of  the  several 
processes  the  palatal  curtain  becomes  differentiated  into  two  parts  :  the 
anterior  undergoes  ossification ;  the  posterior  remains  as  a  movable  cur- 
tain— the  soft  palate.  There  occurs  an  interstitial  formation  of  bone 
outlining  the  dental  portion  of  the  superior  maxillae,  and  soon  a  peri- 
osteum appears  as  in  the  lower  jaw. 

At  the  time  of  birth  the  upper  jaw  is  at  a  stage  of  immaturity 
corresponding  with  that  of  the  lower  jaw.  The  partially  formed 
crowns  of  the  temporary  teeth,  the  incisors,  farthest  advanced  in  devel- 
opment, next  the  first  molars,  then  the  cuspids,  and  finally  the  second 
molars,  are  all  enclosed  in  a  hollow  arch  of  bone,  having  transverse 
divisions  between  each  tooth ;  the  spaces,  or,  as  they  are  called  by 
Tomes,  loculi  of  the  several  teeth,  are  outlined  in  the  degree  of  the  tooth 
development  (Fig.  66).     Behind  the  second  molar  is  the  developing- 

Ftg.  66. 


Jaws  of  a  seven  months'  child.    The  incisors  in  both  maxillae  are  being  erupted  by  the  absorptioa 
of  the  gum  from  their  cutting  edges  and  the  elongation  of  the  roots  by  calcification.    (Tomes.) 

first  molar  of  the  permanent  denture  ;  as  in  the  lower  jaw,  the  dental 
portion  of  the  bone  predominates.  Taking  the  infra-orbital  foramen  as 
a  fixed  point  of  measurement,  the  top  of  the  alveolar  arch  is  but  a 
short  distance  from  the  floor  of  the  orbit.  At  the  time  of  birth  the 
roof  of  the  mouth  is  but  slightly  arched  from  side  to  side.  We  may 
regard,  as  in  the  lower  jaw,  the  main  portion  of  the  superior  max- 
illae at  this  stage  of  development  to  be  a  dental e,  an  alveolar  portion  ; 
and  that  the  body  of  the  bone,  as  in  the  lower  jaw,  is  in  a  foetal  con- 
dition ;  but  when  it  is  observed  that  the  developing  teeth  are  almost 


HISTOLOGY  OF  THE  MATURE  TEETH.  123 

on  a  level  'svith  tlic  palatal  processes,  it  is  evident  that  these  teeth  are 
lodged  in  the  niaxilhe  proper,  and  that  the  course  of  development  cre- 
ates the  major  portion  of  the  alveolar  bone  subsequently.  This  is  nota- 
bly true  of  the  follicles  of  the  permanent  cuspids,  which  occupy  a  posi- 
tion high  up  and  behind  the  roots  of  the  temporary  tooth.  A  pair  of 
dividers  having  one  point  in  the  infra -orbital  foramen,  and  the  other 
measuring  from  that  point  to,  first,  the  symphysis  edge,  and  next  to  the 
posterior  alveolar  edge  will  show,  if  applied  to  jaws  of  successive  ages, 
a  lengthening  in  both  directions.  The  increase  is  most  notably  down- 
ward. The  teeth  shift  their  relations  not  only  to  their  early  environ- 
ment, about  the  level  of  the  palatal  vault,  advancing  toward  the  al- 
veolar border  ;  but,  in  addition,  the  developing  alveolar  process  lengthens 
the  distance  from  the  alveolar  border  to  the  infra-orbital  foramen,  not 
alone  the  alveolar  process  as  generally  understood,  but  the  alveolar  seg- 
ment of  bone  itself  increases  in  size,  until  the  bone  has  the  dimen- 
sions found  in  the  adult.  Measurements  at  this  time  show  that  the 
distance  from  the  infra-orbital  foramen  to  the  alveolar  border  is  greater 
than  the  depth  of  alveolar  process  developed. 

Histology  of  the  Mature  Teeth. 

It  is  only  through  a  study  of  the  embryology  of  the  teeth  that  the 
histology  of  their  tissues  becomes  clear,  and  following  the  course  of  their 
development  fully  explains  the  structure  of  enamel,  dentin,  and  ce- 
mentum. 

ENAMEL. 

Sections  of  enamel  show  the  tissue  to  be  apparently  made  up  of 
hexagonal  prisms,  which  until  recently  were  believed  to  be  homogeneous 
throughout  their  length.  Upon  the  theory  that  enamel  consisted  of  the 
calcified  bodies  of  the  ameloblasts,  hexagonal  prismatic  epithelial  cells, 
there  could  be  no  other  deduction  ;  but  the  researches  of  Andrews,  who 
demonstrated  the  interlacing  basement-stroma  of  enamel,  and  the  later 
work  of  Williams,  which  showed  the  duality  of  enamel-substance,  ren- 
der untenable  the  theory  of  continuous,  homogeneous  prisms.  The 
final  blow  at  the  direct  calcification  theory,  it  will  be  recalled,  is  that 
the  axes  of  enamel-rods  and  of  the  ameloblasts  are  at  wide  variance. 
An  optical  analysis  of  mature  enamel  in  properly  prejiared  specimens 
shows  clearly  the  presence  of  two  substances  (Fig.  67).  The  clear 
spaces  in  the  section  are  the  cementing-substance  binding  together  the 
calcified  globules,  shown  dark  in  the  section.  It  will  be  seen  that  these 
globules  are  superimposed  upon  one  another  in  such  a  manner  as  to  form 
rods  marked  by  transverse  lines.  These  rods  were  formerly  called 
enamel-prisms.     If  a  section  be  subjected  to  the  action  of  a  dilute  min- 


124 


DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 


eral  acid  (HCl),  the  cement-substance  between  the  rods  and  between  the 
individual  globules  dissolves  more  rapidly  than  the  substance  of  the 
globules,  and  there  is  produced  the  beaded  appearance  shown  in  A, 

Fig.  67. 


Section  of  enamel  of  human  tooth.  Photographed  with  Zeiss  apochromatic  lens  and  Powel  and 
Leland  apochromatic  condenser.  The  optical  parts  accurately  centred  and  the  focus  "  critical." 
The  enamel-rods  are  seen  to  be  resolved  into  distinct  sections  (enamel-globules),  the  cement- 
substance  often  passing  entirely  between  the  sections.    X  400.    (Williams.) 

Fig.  68.     Sections  cut  transversely  to  the  long  axis  of  the  rods  exhibit 
the  appearance  shown  in  B,  Fig.  68.     The  action  of  the  dilute  acid 

Fig.  68. 
A 


Enamel-prisms :  A,  fragments  and  single  fibres  of  the  enamel  isolated  by  the  action  of  hydro- 
chloric acid ;  B,  surface  of  a  small  fragment  of  enamel,  showing  the  hexagonal  ends  of  the 
fibres.     X  350. 

upon    such   specimens   causes  enlargement  of  the  spaces   between   the 
hexagons  by  dissolving  the  cementing — the  interprismatic — substance. 


HISTOLOGY  OF  THE  MATURE  TEETH.  125 

The  enamel  of  human  teeth,  and,  indeed,  that  of  animals,  dif- 
fers in  the  relative  amount  of  cementing-substaiice  and  the  number 
of  globules,  and,  again,  in  the  regularity  of  the  distribution  of  the  two. 
In  one  specimen  the  globules  may  so  predominate  that  the  cementing- 
substance  shows  in  sections  as  tine  lines,  in  others  the  globules  may  be 
small,  rounded,  and  surrounded  by  a  relatively  large  volume  of  cement- 
iug-substance.  Again,  at  different  parts  of  the  enamel-rods  both  ar- 
rangements as  to  relative  amounts  of  the  two  substances  may  be  seen. 
It  is  an  apparently  constant  fact  that  the  cementing-substance  is  more 
soluble  in  dilute  acids  than  is  the  substance  of  the  calcified  globules. 

"  When  enamel  deposition  proceeds  with  the  utmost  regularity  stria- 
tion  of  the  rods  is  most  evident  and  most  regular — i.  e.,  is  best  marked 
in  perfect  specimens  of  enamel,  the  striation  representing  the  orderli- 
ness with  which  the  layers  of  globules  are  deposited  "  (Williams). 

The  enamel-rods  are  crossed  at  an  angle  by  transverse  brown  bands, 
the  striae  of  Retzius.  These  are,  as  compared  with  the  size  of  globules, 
broad  bands  which  exhibit  parallelism  with  one  another ;  they  are 
pigmentary  deposits.  The  causes  of  their  presence  are  not  known,  but 
it  is  probable,  from  existing  evidence,  that  they  represent  periodical 
alterations  in  the  process  of  enamel-development.  They  almost  follow 
a  series  of  lines  which  represent  the  outer  boundary  of  the  enamel-cap 
at  different  stages  of  development ;  that  is,  they  are  most  abundant  in 
number  in  the  thickest  portions  of  enamel ;  least  so  in  the  thinnest  por- 
tions about  the  necks  of  the  teeth.  Noting  the  mode  of  formation 
of  the  rods,  it  is  evident  that  they  must  have  a  radial  direction  from 
the  dentin  surface  outward  ;  the  rods  are,  however,  not  straight,  but 
pursue  an  undulating  course — /,  e.,  each  rod  is  wavy.  In  the  cusps  of 
teeth,  bicuspids  and  molars,  the  general  direction  of  the  rods  is  altered, 
so  that  they  appear  to  interlace  in  sections. 

When  the  crowns  of  teeth  have  fully  erupted,  what  remains  of  the 
enamel-organ  is  entirely  cut  off  from  its  source  of  nutrition,  and  in 
all  probability  nutritive  supply  to  this  tissue  ceases  prior  to  the  erup- 
tion ;  it  is  evident,  therefore,  that  any  change  which  occurs  in  the 
enamel  after  the  eruption  is  entirely  apart  from  nutritive  influence.  The 
enamel  contains  at  this  time  all  of  the  materials  entering  into  enamel- 
composition.  It  has  been  asserted  in  the  past,  and,  indeed,  is  even 
believed  at  the  present  time,  that  the  enamel  undergoes  changes  of 
structure  with  age — grows  harder.  Cut  off  from  its  nutritive  source, 
the  only  possible  way  in  which  change  could  occur  would  be  in  a  molec- 
ular alteration  of  the  substance  of  which  enamel  is  formed.  Premis- 
ing that  no  change  whatever  occurs  in  enamel  after  the  disappearance 
of  the  enamel-organ  at  the  completion  of  amelification  is  an  entirely 
warrantable  position,  and  yet  the  possibility  of  such  a  molecular  rear- 


126  DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 

rangement  as  would  alter  both  the  physical  and  the  chemical  properties 
of  enamel-substance  must  be  conceded.  Whether  or  not  enamel  does 
grow  harder  after  its  formation  is  undetermined. 

THE    DENTIN. 

Sections  of  formed  dentin  show  it  to  be  made  up  of  a  calcified  basis- 
substance  penetrated  throughout  its  thickness  by  tubules.  The  latter 
exist  in  such  profusion  as  to  occupy  in  some  specimens  nearly  as  much 
space  in  the  section  as  is  occupied  by  the  basis-substance  itself  (Fig.  69). 
In  other  teeth,  presumably  those  having  a  less  percentage  of  organic 
matter,  the  basis-substance  of  the  dentin  predominates.     The  tubules 

Fig.  69. 


Longitudinal  ground-section  through  the  crown  of  a  cuspid  of  a  man  set.  23.    Wet  ground-section 
stained  by  Golgi's  method:  /,  interglobular  space  ;  .S',  enamel.    X  250.    (Rose.) 

pursue  a  continuous,  wavy,  radial  course  from  the  periphery  of  the  pulp- 
chamber  to  the  junction  of  enamel  and  dentin.  Near  their  termination 
at  the  enamel  the  tubules  divide  and  subdivide  dichotomously.  In 
sections  prepared  after  the  Weil  method,  which  makes  possible  the 
preparation  of  laminse  composed  of  hard  and  soft  tissues  and  outlines 
both  by  means  of  differential  staining,  or,  in  this  case,  by  the  Golgi 
method,  it  is  seen  that  these  dichotomous  branches  take  stain  as  do 
the  contents  of  the  tubules — i  e.,  they  are  the  same  substance.  A 
transverse  section  through  the  dentin  exhibits  sections  of  the  tubules 
(Fig.  70).  In  this  specimen  saturation  of  the  dentin  with  Canada 
balsam  preceded  the  staining,  so  that  the  tubules  are  filled  with 
unstained  balsam,  showing  white.     Two  distinct  substances  are  seen  : 


inSTOLOGY  OF  THE  MATURE  TEETH. 


127 


immediately  bounding  each  tubule  is  a  thick  layer  of  substance  stained 
dark,  and  between  these  circular  anjas  of  staining  are  more  faintly 
stained  areas.  If  sections  be  subjected  to  the  action  of  dilute  acids,  it 
is  seen  that  the  basis-substance  of  the  dentin  is  dissolved  much  more 
rapidly  than  the  surrounding  walls  of  the  dentinal  tubuli — /.  e.,  the 
walls  of  the  dentinal  tubuli  ditter  in  composition  from  the  basis-sub- 
stance of  the  dentin.  These  walls  are  called,  from  their  discoverer,  the 
sheaths  of  Neumann.  *'  If  dry  and  macerated  specimens  of  dentin  be 
subjected  to  the  action  of  dilute  acetic  acid  (Baume),  the  sheaths  of 

Fig.  70. 


N.Sch.. 


Transverse  ground-section  through  the  dentinal  tubules  of  the  first  molar  of  a  child  set.  7: 
V.  Koch's  and  Golgi's  methods.combined.    X  1200.    (Rose.) 


Neumann  around  adjoining  tubules  are  seen  to  be  connected  with  one 
another  by  numerous  transverse  branches."  ^  Specimens  stained  after  the 
Golgi  method  showed  that  these  transverse  connections  take  stain  like  the 
sheaths  of  Neumann,  but  that  no  evidence  of  the  entrance  of  filaments 
of  Tomes'  fibres  can  be  observed.  Tomes'  fibres  being  the  organic 
central  contents  of  the  dentinal  tubule  (see  later).  These  transverse 
branching's  are  most  evident  in  the  most  recently  formed  dentin  ;  least 
evident  in  the  oldest  or  peripheral  dentin.  This  virtually  marks  oif 
the  recently  formed  dentin  into  defined  areas  of  fully  calcified  basis- 
substance,  each  of  which  is  surrounded  by  the  substance  of  which 
Neumann's  sheaths  and  its  branches  are  composed.  From  its  reaction 
to  stains  and  its  behavior  toward  acids  this  latter  substance  is  re- 
garded as  a  transitional  material  between  fully  calcified  dentin  and 
^  Rose,  Dental  Cosmos,  1893. 


128 


DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 


its  organic  basis,  and  a  structure  quite  explicable  through  the  embry- 
ology of  dentin. 

Specimens  of  dentin  subjected  to  the  prolonged  action  of  a  6  per  cent, 
solution  of  acetic  acid  do  not  lose  their  form,  but  become  pliable,  the  cal- 
cium salts  having  been  removed  from  the  organic  matrix.  Rose  states 
that  if  a  section  of  decalcified  dentin  be  placed  on  a  cover-glass  and 
concentrated  nitric  acid  applied,  and  the  slide  warmed,  the  substances 
between  the  sheaths  of  Neumann  and  their  connecting  branches  melt 
away ;  next  the  connecting  branches  disappear,  and  finally  the  sheaths 
themselves.  In  old  specimens  of  dentin  there  is  no  evidence  of  the 
presence  of  transverse  branches  of  Neumann's  sheaths  until  sections 
are  subjected  to  the  action  of  dilute  acids,  when  by  the  formation  of 
bubbles  of  carbon  dioxid  their  presence  becomes  evident.  This  point 
is  of  clinical  significance,  as  it  demonstrates  that  there  are  in  the  den- 
tin lines  of  less  resistance  to  the  action  of  acids. 

It  has  been  shown  by  Hart^  that  the  basis-substance  of  dentin  is 


Fig.  71. 


Main  mass  of  dentin  of  a  temporary  tootli,  stained  with  chlorid  of  gold,  decalcified  with  acetic 
acid:  F,/^,  dentinal  fibres,  partly  vacuoled ;  i?,B,  basis-substance,  traversed  by  a  reticulum. 
X  1200. 

traversed  by  a  fine  network  of  fibres,  a  connective-tissue  stroma  in 
which  the  calcific  process  occurs  (Fig.  71).  Il5se^  regards  these  as 
the  gelatin-yielding  fibres  of  the  dentin. 

In  the  border-ground  between  dentin  and  enamel  and  dentin  and 

^  Dental  Comnos,  1891.  ^  Dental  Cosmos,  1893. 


HISTOLOGY  OF  THE  MATURE  TEETH. 


129 


cementum  the  dentin  nsually  j)ref<ents  a  diflterent  liistological  appearance 
from  the  general  mass  of  tlie  dentin.  Instead  of  the  orderly  snb- 
division  of  the  dentinal  tnbules,  this  portion  of  the  dentin  may  be  occn- 
pied  by  irregular  spaces — interglobular  spaces.  This  particular  layer 
of  tissue  was  named  by  its  discoverer,  Sir  John  Tomes,  the  granular 
layer  (Fig.  72).     As  he  pointed  out,  the  layer  is  much  more  marked 


Ground-section  through  the  root  of  a  human  premolar :  D,  dentin ;  K,  cement-corpuscles ;  0,  osteo- 
blasts ;  Ep,  remains  of  Hertwig's  epithelial  sheath  ;  J,  interglobular  spaces.    X  200.    (Rose.) 


beneath  the  cementum  than  bencnith  the  dentin.  (These  spaces  Avill 
be  discussed  in  Chapter  X.)  It  was  first  pointed  out  by  the  same 
observer  that  the  organic  processes  contained  in  tlie  tubules  of  the  den- 
tin were  direct  prolongations  from  the  peripheral  cells  of  the  dental 
pulp  ;  that  they  were  processes  of  the  dentin-forming  cells — the  odon- 
toblasts ;  these  processes  are  named,  from  their  discoverer,  Tomes' 
fibres.  Investigations  as  to  the  nature  of  these  fibres  have  thus  far 
defined  them  as  protoplasmic  processes ;  they  are  not  connective- 
tissue  fibres,  and  their  identity  with  nerve-fibres  is  disproved,  although 
their  high  degree  of  sensitivity  favors  such  a  conclusion.  The  general 
direction  of  the  tubules  is  at  the  necks  of  the  teeth  and  in  their  root- 
portions  at  right  angles   with   the  axis  of  the  pulp-chamber ;    in  the 

9 


130 


DEVELOPMENT  OF  THE  JAWS  AND  TEETH. 


Margin  of  dental  pulp:  a,  a,  dentinal  fibrils,  pulled  out  of  the  dentin;  b,  b,  membrana  eboris  or 
layer  of  odontoblasts ;  c,  c,  transparent  zone  between  the  odontoblasts  and  the  cells  of  the  pulp 
proper;  (i,  d,  layer  of  cells  closely  packed  together;  e,  e,  bloodvessels;  /,/,  cells  less  closely 
placed  toward  the  central  portions  of  the  pulp.    (Wales'  immersion,  jV  in.  objective.)    (Black.) 


Fig.  74. 


S.I).- 


Od. 


N.T.- 


B.  v.. 


-if ' ' '    ' 


^\U 


•J 


-K.F. 


.C.G 


Section  of  a  tooth-pulp :  B.V.,  main  bloodvessels  of  pulp;  C,  origin  of  capillaries;  iS^.T.,  main 
nerve-trunk;  N.F.,  subdivisions  of  nerve  into  fibrillse ;  O.B.,  odontoblastic  layer;  S.B.,  sec- 
ondary dentin ;  C.G.,  masses  of  calco-globulin.    X  30.    (After  Rose  and  Gysi.) 


HISTOLOGY  OF  THE  MATURE  TEETH. 


131 


crown  portion  they  j^rocecd  radially,  the  centre  of  the    pulp-chamber 
being  the  centre  of  radiation. 


THE    PULP. 


As  foreshadowed  in  the  embryonic  tissue  of  the  dentinal  papilla,  the 
dental  pulp  consists  of  a  connective-tissue  stroma,  an  interlacing  vas- 
cular netw(jrk,  a  layer  of  differentiated  formative  cells,  and  a  neural 


Fig.  75. 


CD. 


I.D. 


P.C.' 


L.F. 


Od. 


Section  of  pulp,  showing  tlic  relations  of  the  odontoblasts  to  the  dentin:  "■'■.,  odontoblasts ; 
T.F.,  Tomes' fibres— odontoblastic  processes;  /./>.,  uucalcified  dentin;  CD.,  calcified  dentin; 
P.C,  pulp-cells.     X  800.    (Rose  and  Gysi.) 

system.     Thus  far,  no  evidences  of  a  lymphatic  system  have  been  dis- 
covered (Fig.  73). 

The  general  disposition  of  the  tissues  of  the  pulp  is  as  follows  :  a 
layer  of  columnar  cells — the  odontoblasts — covering  its  periphery  and 
sending  processes — Tomes'  fibres — into  and  throughout  the  lengths  of 
the  dentinal  tubule  ;  beneath  this  layer  a  closely  interlacing  plexus  of 
non-medullated  nerve-fibres  and  a  capillary  network.  The  middle  por- 
tion of  the  pulp  is  occujned  by  the  trunks  of  the  nerves  and  by  those 
of  the  bloodvessels,  all  of  these  special  tissues  being  supported  by  a 
framework  of  myxomatous  tissue,  a  modified  connective  tissue. 


132 


DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 


If  sections  of  injected  and  properly  stained  pulps  be  viewed  under 
a  low  magnifying  power,  it  is  seen  that  the  arteries  and  nerves  enter  the 
pulp,  and  the  veins  leave  it  by  several  trunks.  Arteries  divide  and 
subdivide  until  they  terminate  in  a  capillary  network  immediately 
beneath  the  odontoblastic  layer.  The  nerves  are  medullated  and  non- 
medullated ;    the  former   soon  lose  their  medullary  sheath,  their  ter- 

FiG.  76. 


A. 


Section  of  developing  tooth  of  rat :  o,  bloodvessels  entering  the  odontoblastic  layer  of  cells  from 
the  pulp ;  b,  dentin.     (Williams.) 


rainals  apparently  ending  in  a  network  beneath  the  odontoblasts.  The 
odontoblasts  (Figs.  73  and  75)  have  the  appearance  of  a  thick,  cellular 
boundary  membrane.  To  make  out  the  details  of  structure  of  the  pulp 
a  magnifying  power  of  400  diameters  must  be  used. 

The  Odontoblasts. — The  boundary  peripheral  cells — the  odonto- 
blasts— closely  resemble  columnar  epithelium,  having  between  the  cells 
but  a  very  small  amount  of  intercellular  substance  (Fig.  75).  During  the 
period  of  development  the  presence  of  a  capillary  supply  has  been  detected 


HISTOLOGY  OF  THE  MATURE  TEETH. 


133 


in  the  odontoblastic  layer  (Fig.  76  and  01).'  It  is  to  be  recalled 
that,  no  matter  how  close  their  resemblance  to  epithelial  cells,  odonto- 
blasts belong  to  the  connective-tissue  group.  Epithelium  never  becomes 
connective  tissue,  nor  can  connective  tissue  ever  become  epithelium, 
although  the  contrary  opinion  has  been  held  by  some  histologists. 
Under  abnormal  conditions,  however,  epithelial  cells  may  and  do  pro- 
liferate in  the  spaces  of  connective  tissue  (see  Carcinoma). 

The  odontoblasts  are  large  cylindrical  cells  which  in  the  pulp  of  the 

Fig.  77. 


OD 


;l/XFSlM^llHii^ 


Pulp  from  the  root  of  a  molar  of  a  man  fet.  40.  Ground-section  after  V.  Koch's  petrifying  method : 
OD,  active  odontoblasts;  ODi,  resting  odontoblasts,  reminding  of  osteoblasts;  P,  fibrillse  of 
the  pulp;  ^,  arteries;  r,  vein  ;  iV.  nerve.    Zeiss  apochrom.    X  250.    (Rose.) 

young  adult  are  closely  massed  together,  the  large  nucleus  occupying 
the  pulpal  extremity  of  the  cell.  This  gives  a  ])ear-shaped  appearance 
to  cells  whose  bodies  have  shrunk  slightly  in  preparing  the  pulp  for 
sections.  Each  cell  is  seen  to  send  one,  and  sometimes  two,  prolonga- 
tions of  its  substance  into  the  dentin — Tomes'  fibres.  Between  the 
1  J.  L.  Williams,  Dental  Cosmos,  1896. 


134  DEVELOPMENT  OF  THE  JAWS  AND  TEETH. 

ends  of  the  odontoblasts  and  the  formed  dentin  a  layer  of  transitional 
or  partially  calcified  dentin  may  be  seen.  At  later  maturity  the 
odontoblasts  appear  to  have  reached  their  physiological  formative-limit 
— they  become  smaller  (Fig.  77).  Under  abnormal  conditions,  how- 
ever the  formative  activity  may  continue  until  but  a  faint  trace  of  a 
pulp-chamber  remains. 

The  Pulp-matrix. — In  the  child  the  stroma,  the  matrix  of  the  pulp, 
appears  to  be  made  up  of  a  loose  myxomatous  tissue,  a  structureless 
basis-substance  traversed  by  bloodvessels  and  nerves ;  it  is  irregularly 
supplied  with  large  corpuscles,  at  first  round,  but  which  subsequently 
develop  filamentous  processes,  each  cell  having  two  or,  it  may  be, 
several,  giving  the  cell  a  stellate  appearance — i.  e.,  they  are  the  cells  of 
myxomatous  tissue.  In  the  body  of  the  pulp  the  cells  are  irregularly 
arranged,  their  fibrillar  processes  forming  a  loose  network.  In  the  root 
or  constricted  portion  of  the  pulp  the  cells  appear  to  exhibit  the  effects 
of  general  compression  and  have  a  spindle-like  form,  and  are  arranged 
with  their  longitudinal  axes  parallel  with  the  axis  of  the  root.  In 
the  mature  adult  the  cells  lessen  in  volume,  and  the  extent  and  number 
of  their  processes  increase.  Manipulation  of  such  pulps  will  show  that 
they  have  increased  in  toughness.  To  the  naked  eye  they  appear  to 
have  become  more  fibrous.  Rose^  has  shown  that  these  fibres  do  not 
yield  gelatin  upon  boiling ;  hence  they  must  be  regarded  as  the  trans- 
formed processes  of  cells,  and  not  connective-tissue  fibres. 

Vascular  System. — The  arteries  of  the  pulp  soon  lose  almost 
entirely  their  muscular  coat,  and  their  external  coat  is  reduced  to  an 
inconsiderable  amount  of  fibrous  connective  tissue ;  the  veins  remain 
for  an  unusual  distance  without  a  marked  muscular  coat.  Before  the 
disappearance  in  the  arterial  walls  and  after  their  reappearance  in  the 
walls  of  the  veins  the  muscular  coat  is  reduced  to  a  layer  of  extreme 
thinness,  so  that  histologically  the  walls  of  the  smaller  vessels  of  the 
pulp  are  made  up  of  an  endothelial  coat,  and  probably  an  elastic  lamina, 
an  attenuated  connective-tissue  coat  surrounded  by  the  loose  stroma- 
tissue  of  the  pulp.  This  histological  datum  has  great  clinical  signifi- 
cance (see  Diseases  of  Pulp). 

The  vascularity  of  the  pulp  decreases  with  age.  "  In  young  teeth 
there  are  a  number  of  arterial  trunks  entering  the  apical  foramen, 
which  lessen  in  number  as  the  passage  lessens  in  size "  (Black).  Soon 
after  the  entrance  of  the  arteries  at  the  apical  foramen  they  divide  and 
subdivide  into  numberless  branches,  and  finally  into  a  capillary  network 
(Fig.  78),  most  marked  immediately  beneath  the  odontoblasts  ;  the  capil- 
laries empty  into  veinules — these  into  vein-trunks  of  relatively  large  size 
as  compared  with  the  arteries.     These  vessels  pass  out  of  the  apical 

1  Dental  Cosmos,  1893. 


THE  CEMENTUM. 


135 


Fig.  7S 


foramen  parallel  with  arteries  and  nerves.  This  anatomical  arrange- 
ment of  arteries,  veins,  and  nerves,  having  passage  through  such  a  con- 
stricted orifice,  is  of  clinical  importance. 

The  Nerves. — The  nerves  of  the  pulp,  even  upon  entry  to  the 
organ,  appear  to  be  both  medullated  and 
non-mednllated.  Whether  they  belong  to 
both  cerebrospinal  and  sympathetic  sys- 
tems is  not  made  out ;  nor  is  their  phys- 
iolojjical  connection  with  the  vessels  of 
the  pulp  determined.  The  ultimate  bun- 
dles of  nerve-fibrillse  appear  to  form  an 
intricate  plexus  immediately  beneath  the 
odontoblasts.  By  the  use  of  Golgi's  stains 
Retzuis  ^  demonstrated  that  in  the  mouse 
the  finer  nerve-fibres  interlace  about  the 
bloodvessels,  the  nerve-trunks  themselves 
following  the  direction  of  the  bloodvessels. 
The  terminal  fibrillse  of  the  nerves  found 
their  way  between  the  odontoblasts,  appar- 
ently terminating  in  knob-like  extremi- 
ties between  the  odontoblasts  and  the  den- 
tin, but  showing  no  evidence  of  penetra- 
tion of  the  dentinal  tubuli.  No  direct 
anatomical  connection  has  been  made  out 
between  the  nerve-fibres  and  the  odonto- 
blasts, although,  as  will  be  shown  later,  their  physiological  connection 
is  evident. 


Point  of  the  pulp  of  an  incisor,  in- 
jected with  Beale's  blue  to  show 
the  bloodvessels,    x  25.    (Black.) 


THE   CEMENTUM. 

The  analogy  between  dentin  and  bone  is  made  out  Avith  some  dif- 
ficulty ;  that  between  bone  and  cementum  is  evident — cementum  is  a 
modified  bone.  Examined  in  gross  mass  the  cementum  is  seen  to  be 
deposited  over  the  entire  root  and  frequently  slightly  overlapping  the 
extreme  edge  of  the  enamel  at  the  neck  of  the  tooth,  this  being  the 
point  at  which  the  first-formed  layers  of  cementum  are  laid  down,  the 
cementum  over  the  apex  of  the  root  being  that  last  formed.  At  the 
period  accepted  as  the  physical  termination  of  tooth-formation  the 
cementum  is  evenly  disposed  over  the  root  of  a  tooth  ;  this  is  some 
time  subsequent  to  the  eruption  of  the  teeth.  Recalling  that  the 
development  of  cementum  is  a  subperiosteal  formation  of  bone,  the 
growth  of  cementum  continues  at  the  sides,  and  particularly  over  the 
ends  of  the  roots,  pari  passu  with  the  decreasing  thickness  of  the  peri- 
'  Gustav  Eetzuis.     See  Catching' s  Compend,  1896. 


136  DEVELOPMENT  OF  THE  JAWS  AND  TEETH. 

cementura,  so  that  at  maturity  the  cementum  is  disposed  as  a  sheath 
over  the  I'oots  of  the  teeth,  thinnest  at  their  necks  and  thickest  over  the 
apices  of  the  roots  and  also  between  the  roots  of  bicuspids  and  molars 
at  their  junction.  Examined  under  sufficient  magnifying  power  the 
cellular  elements  of  the  cementum  are  not  so  easily  made  out  as  are 
those  of  bone ;  but  by  careful  search  one  may  detect  the  irregular 
bodies  of  the  cementoblasts,  which  have  formed  around  them  the  trans- 
lucent substance  of  cementum  and  remain  enclosed  in  their  cement-bed 
as  the  cement-corpuscles. 

Although  there  is  no  decided  appearance  of  lamination  in  the 
cementum,  there  is  clearly  some  evidence  of  stratification,  particularly 
about  half-way  down  the  sides  of  the  roots.  In  a  longitudinal  section 
numerous  fine  lines  may  be  seen  at  right  angles  to  the  lines  of  stratifica- 
tion of  the  cementum ;  these  are  former  Sharpey's  fibres.  In  the 
growth  of  cementum,  as  of  bone,  the  fibrous  elements  of  the  enclosing 
periosteum  have  their  ends  caught  in  the  calcifying  bone,  and  they 
undergo  calcification.  These  lines  represent,  therefore,  old  points  and 
the  method  of  attachment  of  the  pericementum. 

It  has  been  noted  occasionally  that  the  dentinal  tubuli  appear  to 
enter  the  cementum,  although  their  usual  mode  of  termination  is  in  the 
irregular  granular  layer  of  Tomes  underlying  the  cementum.  There 
appears  to  be  a  mechanical  element  determining  the  regularity  of  forms 
of  the  dental  elements  ;  that  is,  they  assume  their  typical  forms  under 
a  definite  pressure,  but  when  this  is  variable  the  histological  forms  are 
altered.  The  first-formed  layers  of  dentin,  both  in  crown  and  root,  it  will 
be  recalled,  are  deposited  not  against  a  rigid  matrix-wall,  but  against 
soft  tissue — the  inner  wall  of  the  enamel-organ,  or  the  epithelial  root- 
sheath  of  Hertwig  ;  this,  no  doubt,  accounts  for  the  disposition  exhibited 
by  the  dentin  of  these  parts  to  assume  irregular  forms. 

THE    PEEICEMENTUM. 

The  pericementum  is  a  somewhat  complex  structure  continuous  with 
the  general  periosteum  of  the  alveolar  process  ;  it  is  also  the  periosteum 
lining  the  inner  alveolar  walls,  is  the  formative  structure  of  the  cemen- 
tum of  the  teeth,  and,  in  addition,  is  the  analogue  of  a  ligament,  for  it 
serves  to  bind  the  root  of  the  tooth  to  its  articular  walls — i.  e.,  those 
of  the  alveolus.  As  will  be  shown  later,  it  is  the  tactile  organ  of 
the  tooth — the  organ  of  localization.^ 

In  general  terms  the  pericementum  is  a  fibrovascular,  neural,  cellular 
structure,  all  of  whose  tissues  perform  important  functions.  Viewed  in 
its  totality,  the  structure  of  the  pericementum  varies  with  age  ;  thickest 

^  The  description  of  the  pericementum  is  largely  derived  from  G.  V.  Black's  work 
upon  the  Periosteum  and  Peridental  Membrane. 


THE  PERICEMENTUM. 


137 


when  root-formation  is  just  complete,  it  becomes  thinner  with  age,  until 
in  some  individuals  it  is  reduced  to  a  lamina  of  extreme  thinness.  Its 
outline-study  divides  the  pericementum  into  three  portions  :  that  adjoin- 
ing the  necks  of  the  teeth,  that  covering  the  apices  of  the  roots,  and  the 
portion  between  them. 

At  the  necks  of  the  teeth  the  pericementum,  as  stated,  is  continuous 
with  the  periosteum  covering  the  external  alveolar  walls,  continuous  as 
regards  its  fibrous  tissues  and  also  by  the  bloodvessels  and  nerves  of  the 
part.     The  neck-edge  of  the  cementum  of  the  tooth  (Fig.  79)  being  at 

Fig.  79. 


Portion  of  the  side  of  a  root  of  a  tooth,  the  gum  and  alveolar  dental  membrane,  and  the  edge  of 
the  bone  of  the  alveolus.  A  band  of  fibres  is  seen  passing  over  the  surface  of  the  alveolus  and 
dividing,  some  passing  upward  into  the  gum,  others  passing  more  directly  across  to  the  ce- 
mentum. Numerous  orifices  of  vessels  cut  across  transversely  are  seen  between  the  tooth  and 
the  bone.    (Tomes.) 

a  higher  level  than  the  edge  of  the  alveolar  process,  the  pericementum 
rises  to  a  higher  point  than  the  true  periosteum.  The  fibrous  tissue  of 
both  pericementum  and  periosteum  is  continuous  with'the  subepithelial 
fibrous  tissue  of  the  gums.  The  epithelial  tissue  of  the  gums  has  about 
the  neck  of  each  tooth  a  rounded  margin  which  leaves  between  gum 
and  tooth  a  V-shaped  depression.  It  has  been  asserted  that  there  are 
infoldings  of  the  epithelial  covering  of  the  gum  at  this  point,  forming 
glands  which  have  a  mucoid  secretion,  the  glands  of  Serres.  Black, 
who  termed  this  epithelial  arrangement  the  gingival  organ,^  later  deter- 

'  American  System  of  Dentistry,  vol.  i. 


138 


DEVELOPMENT  OF  THE  JAWS  AND  TEETH. 


mined  that  it  was  without  the  secretory  function  attributed  to  it.^  As 
in  the  skin,  the  gum  is  arranged  in  vascular  papillae  beneath  the  epi- 
thelium ;  these  are  covered  with  cuboidal  epithelium  overlaid  by  a  thick, 
resistant  covering  of  squamous  epithelium. 

The  PericementurQ  as  a  Ligament. — As  a  ligament  joining  the 
cementum  to  the  walls  of  the  alveolus,  the  pericementum  has  a  definite 
arrangement  of  its  fibrous  elements.  That  portion  of  the  pericementum 
extending  beyond  and  upon  a  level  with  the  periosteum  reflected  from 
the  outer  alveolar  walls  has,  like  the  periosteum,  bundles  of  fibrous  con- 
nective tissue  ascending  toward  the  crown  of  the  tooth  (Fig.  79).  This 
portion  of  the  pericementum  unites  the  pericementum  of  all  of  the 
adjoining  teeth  together  with  the  alveolar  periosteum  in  one  continuous 
sheet  of  tissue  (Fig.  80).     At  a  higher  point  within  the  margins  of  the 


Fig. 


Cross-section  of  the  central  and  lateral  Incisors  below  (toward  the  crowns)  the  rim  of  the  alveolar 
wall,  or  through  the  necks  of  the  teeth,  showing  the  tissues  of  the  septum  and  of  the  gums  ante- 
riorly :  o,  portion  of  central  incisor ;  6,  lateral  incisor ;  c,  pulp-chamber  of  lateral  incisor ; 
d,  d,  cementum  of  central  incisor ;  e,  e,  cementum  of  lateral ;  /,  fibres  of  the  peridental  mem- 
brane, extending  from  tooth  to  tooth  continuously  ;  these  are  fixed  in  the  cementum  of  each 
tooth,  and  form  the  tissue  of  the  septum  ;  g,  g,  fibres  of  peridental  membrane,  which  join  with 
the  coarse  fibrous  tissues  of  the  gums  ;  h,  h,  epithelial  covering  of  the  gums,  J,  J.    (Black.) 


alveolus  the  fibrous  tissue  of  the  pericementum  passes  horizontally  be- 
tween the  root  of  the  tooth  and  its  alveolar  wall,  the  fibres  of  this 
portion  being  the  largest  and  strongest  of  any  part  of  the  ligament. 
At  deeper  points  the  fibres  pass  from  the  alveolar  walls  to  points  of 
the  cementum  farther  distant  from  the  alveolar  margin,  and  the 
tissue  is  arranged  in  looser  bundles.     Around  the  apical  portion  of  the 

^  Periosteum  and  Peridental  Membrane. 


THE  PERICEMENTUM.  139 

root  the  fibres  of  the  pericementum  radiate  from  tlie  cemeutum  to  the 
alveolar  wall.  There  is  no  evidence  in  the  mature  pericementum  of 
an  anatomical  division  of  the  tissue  into  a  dental  and  an  alveolar  peri- 
osteum, although  from  the  mode  of  formation  of  the  structures  and  the 
character  of  tissue  formed  by  the  alveolar  cells  and  the  cemental  cells 
such  a  division  might  be  deemed  rational. 

The  fibres  named  are  of  white  fibrous  connective  tissue  and  their 
arrangement  such  that  the  tooth  is  swung  in  its  socket.  "  The  oblique 
fibres  protect  the  tissues  of  the  apical  space  against  the  stress  of  mas- 
tication and  the  horizontal  fibres  maintain  the  tooth  in  position." 

The  fibres  of  the  pericementum  are  attached  to  cementum  and  to 
the  alveolar  walls  by  large  fibrous  trunks,  which  split  up  into  fasciculi 
of  fibres  in  the  body  of  the  pericementum,  the  fine  fibres  interlacing 
with  one  another.  Interspersed  throughout  the  fibrous  tissue  of  the 
pericementum  are  spindle-shaped  connective-tissue  cells — fibroblasts 
(cells  from  which  fibres  develop) ;  they  are  numerous  in  the  young, 
almost  absent  in  the  aged  pericementum. 

The  other  cellular  elements  of  the  pericementum  are  cementoblasts, 
arranged  in  an  irregular  layer  against  the  cementum,  the  fibrous  bundles 
passing  between  them  for  attachment  to  the  pericementum.  On  the 
alveolar  side  osteoblasts  are  found.  Upon  both  sides  multinucleated 
cells,  osteoclasts  and  odonto-  or  cementoclasts,  are  found  sparsely  at 
irregular  intervals.  They  are,  no  doubt,  increased  in  number  under 
some  conditions,  and  at  times  almost  entirely  absent. 

Black  describes  .peculiar  cellular  bodies  occupying  the  meshes  of  the 
pericementum  near  the  cementum.  These  have  the  appearance  in  sec- 
tion of  glandular  tissue  cut  across.  The  cells  appear  epithelial  in  char- 
acter. The  author  quoted  suggested  that  these  cells  and  collections  of 
cells  belonged  to  a  lymphatic  system  but  now  believes  them  to  be  epi- 
thelial. Considering  the  mode  of  formation  of  the  roots  of  teeth,  it  is 
more  than  possible  that  they  are  the  remnants  of  the  atrophied  epi- 
thelial root-sheath  of  Hertwig. 

The  Vessels  of  the  Pericementum. — The  pericementum  is  a  highly 
vascular  tissue  deriving  its  blood-supply  from  three  sources  :  one  direct, 
two  indirect.  The  direct  supply  is  from  the  vessels  at  the  apical  space  ; 
the  indirect,  by  anastomosis  with  vessels  of  the  alveolar  periosteum 
which  pass  over  the  alveolar  rim,  and  by  anastomotic  connections  with 
the  Haversian  system  of  the  bony  alveolar  walls.  The  vessels  which 
enter  the  apical  space  send  branches  into  the  teeth  supplying  the  pulp  ; 
other  branches  pass  down  the  pericementum,  surrounded  by  the  fibrous 
tissue  of  the  membrane,  and  anastomose  freely  with  the  alveolar  and 
the  periosteal  arteries.  The  vessels  lie  nearer  to  the  alveolar  than  to 
the  cemental  walls.     The  cemental  portions  of  the  pericementum  are 


140  DEVELOPMENT  OF  THE  JAWS  AND   TEETH. 

freely  channelled  by  a  plexus    of  capillaries.     The  veins  pursue  the 
same  course. 

The  Nerves  of  the  Pericementum. — The  nerve-supply  to  the  peri- 
cementum follows  about  the  same  course  as  that  of  the  arteries.  The 
nerves  enter  in  bundles  by  way  of  the  apical  space ;  some  of  them  enter 
the  pulp-chamber;  others  run  along  the  course  of  the  pericementum, 
dividing  and  subdividing  in  their  course.  Other  fibres  enter  by  way  of 
the  Haversian  canals  of  the  alveolar  walls,  which  split  up  and  at  the 
border  of  the  pericementum  form,  with  fibres  from  the  gum,  a  fine  gin- 
gival plexus.  Black  has  observed  in  some  cases  the  existence  of 
Pacinian  corpuscles  as  nerve-terminals  of  the  pericemental  nerves,  but 
believes  that  the  common  mode  of  termination  of  the  fibres  is  in  fine 
naked  filaments. 


CHAPTER  VIII. 
THE  SURGICAL  ANATOMY  OF  THE  TEETH. 

By  the  surgical  anatomy  of  any  part  is  meant  a  description  of  the 
structure  and  those  relationships  of  the  part  which  have  a  bearing;  direct 
or  remote  upon  disease  of  such  parts,  and  a  study  of  those  anatomical 
peculiarities  which  modify  the  nature,  course,  and  treatment  of  such 
diseases.  The  snrgical  anatomy  of  the  teeth,  therefore,  embraces  not 
only  a  study  of  the  structure  of  the  teeth  themselves,  but  also  a  con- 
sideration of  the  environment  of  the  teeth  and  of  all  parts  with  which 
the  teeth  have  direct  anatomical  and  physiological  relationship. 

The  teeth  are  to  be  surveyed  from  two  points  of  view,  mechanical 
and  physiological.  Their  office  being  that  of  the  mechanical  sub- 
division of  the  food,  they  are  to  be  viewed  as  instruments  built  for  that 
purpose.  Like  other  parts  of  the  body,  their  physical  peculiarities  and 
anatomical  relations  are  the  immediate  factors  to  be  considered  in  a 
study  of  the  diseases  affecting  them.  This  includes  a  consideration  of 
all  features  which  are  connected  with  the  vital  processes  and  reactions 
of  the  body,  and  a  study  of  their  nutrition  and  innervation,  of  their 
relationship  with  the  lymphatic  system,  and  of  their  associations  by 
both  continuity  and  contiguity. 

Beginning  at  the  periphery  and  proceeding  toward  the  centre  several 
tissues  are  first  to  be  examined. 

Dental  Tissues. 

For  a  short  period  after  their  eruption  the  crowns  of  the  teeth  are 
covered  by  the  structure  called  Nasmyth's  membrane,  representing, 
doubtless,  in  large  part  the  remnant  of  the  enamel-forming  organ.  As 
soon  as  the  teeth  are  erupted  this  membrane  is  deprived  of  all  nutrition, 
and  is  therefore  a  dead  tissue — foreign  to  the  body.  It  is  soon  worn  off 
the  crowns  of  the  teeth  by  attrition,  except  in  the  deep  sulci  of  the 
bicuspids  and  molars,  and  it  remains  for  some  time  upon  the  enamel 
along  the  gum-margin,  where  it  may  later  serve  as  a  breeding-ground 
for  micro-organisms. 

The  tissue  subjacent,  the  enamel,  is  an  entirely  extra-nutritional 
tissue,  its  source  of  nutrition  disappearing  at  the  termination  of  enamel- 
formation.  Enamel,  once  formed,  cannot  be  influenced  by  any  nutri- 
tional changes  in  its  substance  ;  it  is  a  dead  tissue.     It  is  to  be  viewed, 

141 


142  THE  SURGICAL  ANATOMY  OF  THE  TEETH. 

first,  as  a  structure  designed  to  do  mechanical  work ;  secondly,  as  to  its 
reactions  to  its  physical  and  chemical  surroundings.  Enamel  is  the 
hardest  and  most  rigid  tissue  of  the  body.  "  If  two  blocks  of  equal 
size,  one  of  enamel  and  one  of  dentin,  be  subjected  to  stress,  it  is 
seen  that  the  enamel  block  crushes  at  a  much  lower  stress  than  that 
of  dentin,  the  latter  being  elastic,  the  former  inelastic ;  this  appears 
to  be  true  no  matter  in  what  axis  the  enamel  is  pressed  upon  ;  but 
if  a  layer  of  material  such  as  a  mat  of  soft  gold  be  interposed 
between  the  enamel  and  the  instrument  pressing  upon  it,  its  resistance 
is  much  increased."  ^  If  sections  of  the  crowns  of  teeth  be  made,  it 
will  be  seen  that  there  is  a  mechanical  arrangement  of  the  enamel  ele- 
ments and  substance  fitted  to  counteract  the  innate  brittleness  of  the 
substance  itself.  First,  the  enamel  surfaces  are  highly  polished,  so  that 
there  is  a  minimum  of  friction  between  opposing  teeth  ;  any  increase  of 
roughness  or  any  jaggedness  of  enamel  robs  the  teeth  of  this  advantage. 
Secondly,  it  will  be  noticed  that  nearly  all  of  the  enamel  surfaces  which 
are  brought  into  action  during  mastication  receive  mechanical  support 
through  an  appropriate  arrangement  of  enamel-masses.     In  the  incisor 

Fig.  81. 


Architectural  structure  of  au  incisor. 


teeth,  whose  function  is  the  cutting  off  of  defined  masses  of  food,  they 
are  primarily  blades,  which  pass  one  another  as  the  blades  of  shears, 
dividing  substances  which  are  placed  between  them.  It  will  be  readily 
seen  that  in  this  operation  the  upper  incisors  are  subjected  to  greater 
stress  than  are  the  lower.  The  tendency  is  to  break  away  the  blade  of 
the  tooth  (Fig.  81,  hd) ;  this  is  mechanically  guarded  against  by  the 
presence  of  two  buttresses  (6,  6)  merging  with  the  angles  of  the  cutting- 
blade,  increasing  in  thickness  as  they  descend  to  join  a  half  girdle  at 
the  neck  of  the  tooth  (g).  The  outer  faces  of  the  blade  are  braced  by 
three  stanchions  of  enamel  {s,  s,  s),  one  in  the  middle  and  one  at  each 
lateral  edge. 

In  the  cuspid  (Fig.  82),  which  maybe  regarded  primarily  as  a  pierc- 
ing instrument  and  secondarily  as  two  cutting-blades  set  at  an  angle 
with  one  another,  the  cutting-blades  are  set  with  their  edges  at  an  obtuse 
^  G.  V.  Black,  Dental  Cosmos,  1895. 


DENTAL  TISSUES. 


143 


angle,  which  forms  tlic  piercing-point.  The  edges  have  each  a  lateral 
buttress  (6,  b),  uniting  with  a  cervical  half  girdle,  and,  in  addition,  a 
thick  buttress  (63)  descends  from  the  point,  merging  into  the  girdle. 
Upon  the  outer  face  there  are  three  stanchions  (.s',  .s-,  .s"),  of  which  the 
middle  one  is  most  marked.     In  the  bicus])id  teeth,  which,  anatomically 

Fig.  82. 


Architectural  structure  of  a  cuspid. 

analyzed,  are  cuspids  slightly  modified  and  bound  together,  as  indeed  are 
also  the  molar  teeth,  in  both  molars  and  bicuspids  then,  appropriate 
architectural  arrangement  of  the  elements  may  also  be  observed.  The 
upper  bicuspids  are  seen  to  be  two  cuspids  with  their  cusps  or  points 
upon  opposite  sides.  It  is  seen  that  these  two  elements  are  bound 
together  by  two  lateral  girders  or  bands  which  join  the  lateral  girders 
of  the  cuspid  elements.  A  similar  arrangement  is  found  in  the  lower 
bicuspids  (Fig.  83,  g,  g),  although  here  the  double  cuspid  character  of 
the  teeth  is  not  so  pronounced  as  in  the  upper. 

The  upper  molars  (Fig.  84)  are  structurally  composed  of  three  cuspid 
elements  bound  together  (g,  g),  although  in  the  first  and  second  molars 
a  supplementary  piece  is  found,  which  is  weakly  girdered  to  the  second 
of  the  cuspid  elements.  It  will  be  observed  that  this  additional  piece 
(c),  whose  junction  with  the  tricuspid  arrangement  is  marked  by  a  sul- 
FiG.  83.  Fig.  84.  Fig.  85. 


Architectural  elements  of  bicuspids  and  molars. 

cus,  is  an  element  of  weakness.  In  the  second  molar  the  additional  piece 
is  smaller  and  not  so  well  attached  ;  in  the  third  molar  it  is  usually  absent. 

The  lower  molars  (Fig.  85)  are  composed  of  four  cuspid  elements, 
the  two  outer  and  the  two  inner  beinc:  bound  together  bv  an  anterior 
and  a  posterior  girder  (g,  g).  Upon  the  first  and  third  molars  a  disto- 
buccal  supplementary  piece  (c)  is  girdered  to  the  quadrangular  mass. 

In  all  of  the  bicuspids  and  molars  the  cuspid  character  of  each  cusp 


144  THE  SURGICAL  ANATOMY  OF  THE  TEETH. 

is  well  maintained  in  its  individual  buttresses.  The  buttresses  of  the 
lower  incisors  and  cuspids  are  much  less  pronounced  than  in  the  upper 
incisors.  The  bicuspids  and  molars,  the  stress  upon  whose  cuspid  ele- 
ments is  mainly  lateral,  have  a  buttress  and  girder  arrangement  to  resist 
fracture  through  such  a  stress. 

It  is  evident  that  a  tooth  which  has  lost  any  portion  of  these  sus- 
taining structures  becomes  mechanically  weakened  in  proportion  to  the 
extent  of  the  loss.  If  the  lateral  girders  of  a  bicuspid  or  molar  be  lost 
through  decay,  or  are  cut  through,  the  tendency  to  fracture  of  the  parti- 
ally unbound  cusps  is  much  increased.  If  decay  in  an  incisor  involve 
the  lateral  girders  of  the  tooth,  the  strength  of  the  cutting-blade  becomes 
correspondingly  weakened. 

If  sections  of  the  several  teeth  be  made  and  viewed  under  a  low 
magnifying  power,  it  will  be  seen  that  the  elements  of  which  enamel  is 
composed  have  an  arrangement  admirably  fitted  to  resist  the  stress  to 
which  any  particular  mass  of  enamel  is  subjected.  If  a  mass  of  enamel 
be  detached  from  a  tooth,  and  attempts  be  made  to  cut  it  with  steel 
instruments,  it  will  be  found  that  while  the  hardest  steel  fails  to  cut 
it,  a  chisel-edge  may  be  made  to  break  away  portions  of  the  tis- 
sue ;  this  occurs  readily  only  when  the  tool-edge  is  applied  in  the  direc- 
tion of  the  enamel-rods  ;  if  applied  at  right  angles  to  the  enamel-rods, 
portions  are  broken  away  only  with  much  difficulty,  and,  as  a  rule, 
the  hardest  of  tool-steel  fails  to  make  any  impression  upon  a  perfectly 
polished  enamel  surface.  Examining  prepared  sections  of  entire  teeth, 
it  will  be  seen  that  the  enamel-rods  are  arranged  with  their  longitud- 
inal axes  in  such  positions  that  in  the  impact  of  mastication  stress  is 
received  upon  the  ends  of  the  rods  in  the  lines  of  greatest  resistance.^ 
Defects  in  the  enamel,  such  as  described  under  malformations  of 
the  teeth,  have  a  direct  and  important  surgical  bearing. 
Fig.  86.  Enamel  appears  to  diifer  widely  as  to  its  physical  strength, 

and  also  in  its  degree  of  solubility  in  acids.  As  will  be 
detailed  under  the  head  of  caries  of  the  enamel,  fissures 
affi">rd  opportunities  for  the  lodgement  of  food-debris, 
the  nidus  of  lactic  fermentation  ;  and,  again,  the  calcic 
cementing-substance  lying  between  the  calcified  globules 
of  the  enamel-rods  is  more  soluble  in  lactic  acid  than 
are  the  globules ;  hence  enamel  in  which  cementing- 
substance  is  in  excess  is  less  resistant. 

The  enamel  is  thickest  and  in  greatest  amount  where 

it  receives  the  greatest  stress,  shading  off  until  at  the 

neck  of  the  tooth  it  terminates  in  a  feather-edge,  whose 

outline  is  that  of  the  gum-margin  of  the  particular  tooth,  about  one- 

^  See,  later,  Mechanical  Arrangement,  in  this  connection. 


SURGICAL  ANATOMY  OF  THE  DENTIN.  145 

sixteenth  of  an  inch  below  which  margin  the  enamel-edge  is   found, 
overlaid  slightly  by  the  thin   edge   of   the  cementum  (Fig.  86). 

Surgical  Anatomy  of  the  Dentin. 

Dentin  is  the  second  hardest  tissue  of  the  body.  The  texture  of 
this  tissue  changes,  as  does  that  of  the  other  connective  tissues,  with  age. 
In  the  young  or  immature  dentin  there  is  a  greater  ratio  of  organic 
matter  than  in  the  dentin  of  a  middle-aged  person.  The  increase  of 
calcium  salts,  the  inorganic  constituents,  has  been  shown  by  Black  ^  not 
to  be  so  great  as  was  formerly  believed.  The  average  amount  of  cal- 
cium salts  in  teeth  at  the  age  of  11  years  is  found  to  be  62.26  per 
cent. ;  at  53  years  the  percentage  is  64.56.  The  average  specific  gravity 
at  11  years  is  1.066,  and  at  63  years  2.109.  While  in  the  main  the 
increase  of  specific  gravity  corresponds  with  the  increase  of  calcium 
salts,  it  is  not  constant.  Between  the  ages  of  twenty  and  forty  years 
there  appears  to  be  a  cessation  in  the  increase  of  calcium  salts. 

Dentin  is  an  elastic  substance :  a  cube  of  yf  ^  inch  side  under 
a  stress  of  150  pounds  is  compressed  4  per  cent,  of  its  thickness,  resum- 
ing its  form  after  removal  of  the  pressure.  Under  a  pressure  of  238 
pounds  the  cube  is  crushed.  Clear  and  translucent  dentin  has  a  high 
crushing  stress  ;  in  opaque  specimens  it  is  much  lower.  An  increase  in 
the  percentage  of  calcium  salts  diminishes  the  elasticity  of  dentin ;  but 
the  amount  of  crushing  stress  appears  to  be  governed  more  by  the  con- 
dition of  the  organic  matrix  than  by  the  percentage  of  calcium  salts  or 
the  density.  When  the  nutrition  of  the  dentin  is  interfered  Avith  by  sec- 
ondary deposits,  or  destroyed  through  death  of  the  dental  pulp,  the 
dentin  appears  to  diminish  in  strength,  as  seen  in  the  abraded  teeth 
of  elderly  persons. 

The  average  percentage  of  organic  matter  in  dentin  is  25.36  ;  this 
diminishes  as  the  density  increases.  Black  believes  that  the  condition 
of  the  organic  matrix  of  the  teeth  has  more  to  do  with  the  strength  of  the 
teeth  than  have  the  density  and  specific  gravity.  The  proportion  of 
organic  matter,  as  pointed  out  by  INIiller,^  is  not  an  exact  measure  of  the 
hardness  of  the  dentin,  for  many  interglobular  spaces  and  wide  tubules 
may  account  for  a  high  percentage  of  organic  matter,  and  yet  the  dentin 
of  the  tooth  be  very  dense. 

The  dentin  presents  at  least  three  distinct  factors  for  consideration 
in  studying  diseases  which  aifect  it  :  first,  the  basis-material,  the  calcified 
matrix  of  the  tissue ;  secondly,  the  partially  calcified  tubes  which 
surround  the  third  factor,  the  vital  protoplasmic  filaments  of  the  den- 

^  Denial  Cosvios,  1895.     Tlie  statements  made  relative  to  the  physical  properties  of 
dentin  are  mainly  from  the  same  source. 
^  Micro-organisniH  of  the  Human  Mouth. 
10 


146  THE  SURGICAL  ANATOMY  OF  THE  TEETH. 

tin  which  penetrate  its  substance  and  traverse  it  from  the  periphery 
of  the  pulp  to  the  periphery  of  the  dentin.  The  calcified  basis-sub- 
stance of  dentin  is  soluble,  as  is  the  enamel  of  the  teeth,  in  dilute  acids, 
such  as  lactic  acid,  produced  by  the  fermentation  of  carbohydrates. 
When  subjected  to  the  action  of  dilute  acids  it  is  (;hanged  from  the 
material  exhibiting  the  strength  noted  above  into  a  mass  of  about  the 
consistence  of  cartilage,  or  softer ;  deprived  of  its  calcium  salts,  it  still 
retains  its  form.  Diiferent  specimens  of  dentin  exhibit  different  solu- 
bilities. The  differences  in  the  percentages  of  calcium  salts  and  in 
density  do  not  appear  to  be  sufficient  to  explain  differences  of  solubility. 
"  The  calcium  salts  appear  to  be  present  in  the  teeth  and  bony  tissues 
in  a  combination  represented  by  {FO^f^Sii^CO^,  or  saturated  calcium 
phosphate-carbonate,  in  a  combination  which  corresponds  with  apatite, 
(PO ^^Csi^^l^,  phosphate-fluorid  of  calcium."^ 

It  is  not  known  how  this  material  is  combined  with  the  basis-sub- 
stance, the  glue-giving  substance  of  the  dentin  ;  "  whether  it  is  a  chemical 
precipitation,  or  whether  there  is  a  chemical  union  between  the  organic 
and  inorganic  constituents.  In  view  of  the  mode  of  formation  of  calco- 
globulin,  the  basis  of  such  tissues,  it  is  probable  that  the  latter  con- 
dition exists.  "We  should  expect  to  find  dentin  hard  or  soft  according  as 
this  union  is  firm  or  unstable."  ^ 

The  general  dentin-substance  is  to  be  viewed  as  an  interstitial  sub- 
stance, as  formed  material  which  in  itself  necessarily  plays  a  passive 
part  in  the  disease-processes  of  dentin.  It  has  been  held  that  the  den- 
tin undergoes  retrogressive  changes,  particularly  a  decrease  in  the 
amount  of  calcium  salts  in  the  tissue,  not  due  to  the  action  of  extrinsic 
causes.  As  a  typical  example  of  this  alleged  metamorphosis  are  given 
the  changes  occurring  during  pregnancy,  when  the  dentin  of  the  teeth  has 
been  said  to  suffer  a  resorption  of  calcium  salts ;  when  a  more  favorable 
physical  condition  obtains,  a  re-deposition  of  calcic  matter  is  said  to 
occur,  restoring  the  original  density  of  the  teeth.  Black's  analyses 
indicate  that  no  such  resorption  and  deposition  occur.  The  basis  of 
this  belief  was  in  the  undoubted  fact  that  during  gestation  the  teeth  of 
the  mother  suffer  markedly  from  dental  caries. 

The  researches  of  the  same  observer  showed  that  there  is  a  greater 
variation  in  the  density  and  specific  gravity  of  the  individual  teeth  of  a 
denture  than  is  found  in  the  general  average  density  of  many  persons. 

In  line  Avith  the  same  line  of  reasoning  which  formulated  the 
hypothesis  of  resorption  and  re-deposition  of  calcic  matter  should  be 
mentioned  the  belief  of  histologists  of  the  Heitzmann  school  in  the 
possibility  of  dentin  returning  to  its  embryonic  form  ;  no  sufficient  evi- 
dence having  been  adduced  in  support  of  such  a  belief,  it  must  be  set 

^  Hoppe-Seyler,  quoted  by  Miller,  Micro-organisms  of  the  Human  Mouth.         "■'  Ibid. 


SURGICAL  ANATOMY  OF  THE  DENTIN.  147 

aside,  for  in  addition  there  are  numerous  evidences  that  no  such  change 
ever  occurs. 

Sections  of  teeth  wliieh  luive  been  subjected  to  the  prolonged  action 
of  dikite  acids  show  that  the  dentin  immediately  surrounding  the  pro- 
toplasmic filaments  from  the  odontoblasts  is  more  resistant  to  the 
action  of  the  acids  than  the  formed  material  of  the  dentin.  Noting 
this  comparative  insolubility,  this  portion  of  the  dentin  (Neumann's 
sheaths)  has  been  accepted  as  a  partially  calcified  tissue.  Regarding 
the  general  substance  of  the  dentin  as  a  fuUv  calcified  tissue  and  Neu- 
mann's  sheaths  as  partially  calcified  and  probably  transitional  tissue,  it 
becomes  a  reasonable  deduction  that  any  future  change  in  the  density 
of  the  dentin  or  any  increase  in  calcic  deposits  cannot  extend  be- 
yond the  periphery  of  Neumann's  sheaths.  This  agrees  entirely  with 
the  condition  found  in  the  teeth  of  the  aged,  where  the  dentinal  fibrillse 
are  smaller  and  the  lateral  processes  of  Neumann's  sheaths  have  almost 
disappeared.  New  dentin  forms  then  at  the  expense  of  the  size  of  the 
dentinal  fibrillse. 

INTERGLOBULAR   SPACES. 

If  many  specimens  of  dentin  be  examined,  it  will  be  noted  that  in 
some  of  them,  notably  in  that  portion  of  dentin  underlying  the  cemen- 
tum,  and  less  marked  in  the  sub-enamel  portion,  the  general  striation 
produced  by  the  presence  of  the  dentinal  tubuli  is  interrupted  and 
broken  into  by  irregular  spaces — the  granular  layer  of  Tomes.  In 
some  specimens  irregularly  shaped  areas  are  found  widely  distributed 
throughout  the  dentin,  and  it  will  be  observed  that  the  dentinal  tubuli 
frequently  traverse  such  spaces,  being  continuous  upon  both  sides  and 
through  them.  These  are  designated  interglobular  spaces;  during  life 
they  are  filled  with  soft  uncalcified  material  ;  they  represent  areas  of 
non-calcification,  apparently  an  indication  that  the  calcic  salts  of  dentin 
are  deposited  in  a  previously  formed  soft  matrix. 

DENTINAL    FIBRILL.E. 

Occupying  each  dentinal  tubule,  and  following  its  branches,  those 
dichotomous  branches  beneath  the  enamel,  are  processes  from  the  periph- 
eral cells,  the  odontoblasts  of  the  pulp.  Much  speculation  is  still  in- 
dulged in  as  to  the  precise  nature  of  these  processes.  The  most  striking 
feature  noted  in  connection  with  them  is  their  variable  sensitivity.  When 
dentin  denuded  of  enamel  is  brought  in  contact  with  acids,  and  frequently 
with  sweet  substances,  a  sensitivity  is  exhibited  which  varies  in  degree 
with  individuals.  The  same  result  obtains  when  pressure  is  brought  to 
bear  upon  such  surfaces,  or  when  ai)plications  of  heat  or  cold  are  made  to 
them.     As  will  be  noted  later,  these  cells  connected  with  the  pulp,  an 


148  THE  SURGICAL  ANATOMY  OF  THE  TEETH. 

organ  which  has  no  sense  of  location,  do  not  localize  sensation ;  the 
discomfort,  pain,  or  anguish  which  may  be  induced  by  the  contact 
of  irritating  substances  is  vaguely  located  in  that  branch  of  the  di- 
vision of  the  fifth  nerve  involved.  This  sensitivity  has  led  to  the 
inference  that  these  protoplasmic  processes  are  in  reality  nerve-fila- 
ments;  this  one  feature  supports  such  a  belief;  numerous  other  data 
contradict  it.  The  processes  have  been  observed  as  arising  directly 
from  the  bodies  of  odontoblasts,  but  as  yet  no  nerve-fibrils  have 
been  detected  terminating  in  the  odontoblasts.  To  regard  the  odonto- 
blasts as  special  nerve-terminals  would  be  certainly  not  irrational,  but 
until  nerve-fibrils  are  discovered  ending  in  the  odontoblasts  the  question 
is  sub  judioe. 

Retzuis  observes  ^  by  the  use  of  Golgi's  stain  that  the  nerve-fibrils 
of  the  pulp  appear  to  penetrate  between  the  odontoblasts  and  terminate 
between  them  and  the  dentin.  The  only  certain  datum  is,  that  these 
fibrillse  or  processes  have  the  power  of  receiving  and  transmitting  sensa- 
tion equivalent  to,  if  not  identical  with,  that  possessed  by  nervous  tis- 
sues. It  is  certain  also  that  they  are  portions  of  the  dentin-building 
cells,  and  probably  possess  in  some  degree  the  same  constructive 
function. 

The  Pulp  and  Its  Chambers. 

The  pulps  of  the  teeth  are  closely  bounded  at  all  parts  by  dentinal 
walls ;  the  chamber  of  lodgement  represents,  therefore,  the  precise  size 
and  form  of  the  enclosed  pulp.  The  pulp-chambers  have  forms  which 
correspond  quite  closely,  but  not  entirely,  with  the  forms  of  the  partic- 
ular teeth.  If  sections  be  made  in  three  diameters  of  the  teeth,  these 
correspondences  in  form  are  readily  seen,  and  divergences  are  observed 
which  are  of  much  surgical  interest.  Nothing  but  general  rules  can  be 
given  as  to  these  variations  from  general  types,  as  the  variations  may 
assume  very  diverse  characters  (see  Figs.  103-113).  The  pulp  is  ana- 
tomically divided  into  two  parts  :  that  occupying  the  crown  of  the  tooth 
is  called  the  body  of  the  pulp,  and  that  occupying  the  roots  the  radicular 
portion  or  portions.  The  prolongations  from  the  body  of  the  pulp 
which  correspond  with  the  positions  of  the  cusps  are  called  the  horns 
or  cornua  of  the  pulp.  It  will  be  observed  in  many  specimens  that  the 
cornua  of  pulps,  notably  of  the  upper  lateral  incisors  and  upper  first 
bicuspids,  very  frequently  extend  as  sharp  and  unduly  long  projections. 
It  will  also  be  seen  by  a  reference  to  Figs.  87-102  that  the  distance 
from  the  exterior  walls  of  the  teeth  to  the  pulp-chambers  is  much  less 
at  the  necks  of  the  teeth  than  at  other  parts.  This  is  particularly  notable 
in  connection  with  the  upper  molars  ;  the  distance  from  the  exterior  to 
the  pulp-chamber  at  the  cervico-mesio-buccal  angle  is  frequently  very 
'  Catching's  Compend,  1896. 


THE  PULP  AND   ITS  CHAMBERS. 


149 


slight.     Another  peculiarity  of  tolerable  constancy  is  the  nearness  of 
the  body  of  the  pulp  to  the  cervico-distal  portion  of  the  lower  molars. 


Fig.  87. 


Fig.  88. 


Fig.  89. 


Fig.  90. 


Fig.  91. 


Fig.  92. 


Fig.  93. 


Fig.  94. 


Sections  of  upper  teeth,  showing  shapes  of  pulp-chambers  and  their  positions.  Figs.  92  and  93, 
first  figures,  represent  sections  through  the  buccal  roots  of  upper  molars ;  second  figures  are 
sections  through  the  palatal  root  and  portion  of  the  anterior  buccal  roots. 

While,  as  a  rule,  the  external  configuration  of  a  tooth  is  a  fair  guide  to 
the  shape  of  the  pulp-chamber,  variations  are  so  common  that  proximity 
to  the  pulp  in  a  carious  cavity  is  more  accurately  determined  by  elicit- 


150 


THE  SURGICAL  ANATOMY  OF  THE  TEETH. 


ing  subjective  symptoms  than  by  the  objective  evidence  of  the  depth  of 
the  cavity. 

Figs.  103-113  exhibit  formalin-gelatin  casts  of  pulp-chambers/ 
showing  the  great  irregularities  of  form  which  pulp-chambers  may 
assume,  and  yet  give  no  external  evidence  of  such  irregularities. 
Figs.  107-110  show  the  outline-forms  of  the  crown  portions  or  bodies 
of  dental  pulps. 

Fig.  95.  Fig.  96.  Fig.  97. 


Fig. 


Fig.  99, 


Fig.  100. 


Fig.  101. 


Fig.  102. 


Sections  of  lower  teeth,  showing  shapes  of  pulp-chambers  and  their  positions.  Fig.  101  shows  a 
section  through  the  anterior  root  of  a  second  molar ;  an  antero-postero-longitudinal  section 
would  resemble  Fig.  100. 

The  pulp-chamber  decreases  in  size  with  age,  so  that  in  some  cases  it 
is  almost  obliterated  to  the  end  of  the  root.  Secondary  deposits  (see 
Secondary  Dentin)  may  fill  portions  of  the  cavity  and  reduce  its  size  in 
almost  any  direction.  As  will  be  shown,  these  deposits  may  occupy 
the  greater  bulk  of  the  pulp,  and  yet  the  pulp-chamber  remain  of 
normal  size. 

1  W.  H.  Richards,  Dental  Cosmos,  1896. 


THE  PULP  AND  ITS  CHAMBERS. 


151 


PULP    AND    CHAMBERS    OF    TEMPORARY    TEETH. 

The  same  rule  as  to  the  general  size  and  configuration  of  the  pulp- 
chamber  noted  in  connection  with  the  permanent  teeth  holds  good  in 

Fig.  103. 


Fig.  104. 


the  temporary  teeth,  with  this  diiFerence,   however  :   it  is  frequently 
found  that  the  relative  size  of  the  pulp-chambers  is  greater  than  in  the 


152 


THE  SURGICAL  ANATOMY  OF  THE  TEETH. 


permanent  teeth,  so  that  exposure  of  the  pulp  results  soon  after  caries 
has  invaded  the  dentin.     The  radicular  portions  of  the  pulp-chambers 

Fig.  105. 


Fig.  106. 


of  the   temporary  teeth  when   fully  developed   are   frequently  much 
attenuated. 


THE  PULP  AND  ITS  CHAMBERS. 


153 


The  pulp  of  the  tooth  contains  several  factors  of  surgical  interest : 
first,  its  vascular,  next  its  neural  supply.    The  pulp  is  not  provided  with 

Fig.  107. 


1  A    M  k 


^^P^':  3BR~» 


Fig.  108. 


lymphatics,  so  that  effusions  which  occur  in  its  substance  must  be  taken 
up  bv  the  veins  or  remain  in  the  stroma  of  the  pulp.     The  third  ele- 


154 


THE  SURGICAL  ANATOMY  OF  THE  TEETH. 


ment  of  interest  is  found  in  the  layer  of  odontoblasts,  cells  which 
possess   a   persistent   formative   and   sensory    function,  and   next   the 


Fig.  109. 


Fig.  110. 


stroma  of  the  pulp,  its  framework.     The  formative  cells  of  the  pulp, 
as  will  be  noted  later,  are  responsive  to  stimulation,  and  when  stimu- 


THE  PULP  AND  ITS  CHAMBERS. 


155 


lilted  exhibit  an  exaltation  of  function  expressed  in  heightened  sensi- 
tivity and  formative  activity.     These  cells,  arranged  in  a  layer  of  toler- 


FlG.  111. 


Fig.  112. 


able  regularity,  one  cell  deep,  are  by  mutual  pressure  forced  into  an  ar- 
rangement resembling  that  of  cylindrical  epithelium,  but  having  a  slight 


156  THE  SURGICAL  ANATOMY  OF  THE  TEETH. 

space  between  adjoining  cells.  The  odontoblasts  appear  to  abut  directly 
with  the  dentin,  one  or  more  protoplasmic  processes  passing  from  each 
cell  into  dentinal  tubuli.  With  increasing  age  the  odontoblasts  appear 
to  suffer  atrophic  changes  (Fig.  76)  (Rose).  Beneath  the  odonto- 
blasts and  penetrating  the  odontoblastic  layer  for  some  depth  in  the 
developing  teeth  is  a  loop-work  arrangement  of  capillaries  (Williams). 

Fig.  113. 


The  arterial  supply  to  the  pulp  enters  the  apex  of  the  root  through 
several  branches,  which  subdivide  and  appear  to  lose  their  muscular 
coat  at  an  early  period  of  subdivision.  The  capillary  distribution  is, 
as  stated,  in  a  loop  arrangement  beneath  the  odontoblastic  layer.  The 
capillaries  join  veins  of  very  large  size,  in  which  the  middle  coat  ap- 
pears to  be  absent  for  a  long  distance.  It  is  evident,  then,  that  should 
pulp  arteries  and  veins  lacking  this  muscular  coat  be  subjected  to  in- 
creased intra v^ascular  tension,  danger  of  injury  to  their  walls  is  imminent, 
and  occurs  in  hypersemic  and  inflammatory  conditions. 

The  nerves,  entering  by  way  of  the  apical  foramen,  are  both  medul- 
lated  and  non-medullated ;  in  the  peripheral  distribution  all  of  the  fibres 
are  non-medullated.  AVhether  the  non-medullated  fibres  are  purely  vaso- 
motor, and  the  medullated  the  sensory  fibres,  is  not  determined.  A 
point  of  much  surgical  interest  relates  with  the  sensory  function  of  the 
pulp  nerves.  As  emphasized  by  Black,-  the  pulp  is  a  truly  internal 
organ,  and,  like  many  other  internal  organs,  it  has  no  sense  of  location 
^  American  System  of  Dentistry,  vol.  i. 


CEMENTUM  AND  PERICEMEyTUM.  157 

— /.  c,  it  is  not  the  touch-t)rgan  of  the  tooth,  so  that  when  subjected  to 
irritation  these  nerves  react  as  do  tlie  nerves  of  other  typical  internal 
organs — reflect  the  sensation  to  some  <jther  branch  of  the  same  nerve. 
The  classical  illustration  of  this  phenomenon  is  the  pain  of  certain 
hip-joint  diseases  :  the  pain  is  not  felt  at  the  disease-seat,  but  u[)on  the 
inner  side  of  the  knee  ;  the  pains  of  hepatic  disorders  are  referred  to 
the  right  shoulder-blade  ;  those  of  inflammation  of  the  eye-curtain,  the 
iris,  to  the  brow.^  This  is  a  fact  of  great  clinical  importance  in  den- 
tistry, viz.,  pains  due  to  disorders  of  the  pulp  are  not  accurately  located, 
but  are  referred  to  distant  points.  The  pulp  nerves  are,  however,  sin- 
gularly intolerant  of  pressure,  responding  in  painful  paroxysms  to  any 
pressure,  internal  or  external. 

The  stroma  of  the  pulp  has  a  distinct  surgical  interest.  It  is  to  be 
recalled  that  originally  the  pulp  consisted  of  a  mass  of  undifl'erentiated 
mesoblastic  cells  in  a  structureless  basis-substance.  Later,  some  of 
these  cells  become  differentiated  into  dentin-forming  cells  ;  the  dentin 
is  finally  deposited  in  a  finely  fibrillated  stroma  of  fine  gelatin-yielding 
fibres.  At  maturity  the  cells  of  the  pulp  are  of  a  myxomatous  type, 
contained  in  an  apparently  structureless  matrix ;  of  polygonal  form  in  the 
crown  of  the  pulp,  these  cells  show  a  semblance  to  a' fibrillated  arrange- 
ment in  the  radicular  portion  of  the  pulp.  It  has  been  shown  by  R5se  ^ 
that  these  cells  and  their  processes  are  not  ordinary  connective-tissue  cells  ; 
they  do  not  yield  gelatin  upon  boiling.  As  the  pulp  increases  with  age 
the  bodies  of  the  cells  grow  smaller  and  their  fibrillar  processes  become 
more  marked,  until  in  an  old  tooth  an  appearance  of  fibrous  tissue  is 
seen.  The  matrix-cells  are  of  pathological  interest  from  the  fact  that 
they  appear,  under  some  conditions,  to  assume  the  formative  office  of 
odontoblasts,  deposits  of  dentin  occurring  in  the  pulp-substance.  The 
changes  which  occur  with  age  in  the  tissue  of  the  pulp  may  be  likened 
to  sclerosis. 

Cementum    and  Pericementum. 

At  the  apex  of  the  root  the  arterial  and  neural  supply  to  the  interior 
of  the  tooth  is  continuous  with  the  same  structures  to  the  external  vital 
structures  of  the  tooth,  viz.,  the  pericementum  and  the  cementum. 

Tlie  pericementum  is  the  touch-organ  of  the  tooth,  the  nerves  of 
which  possess  the  sense  of  location.  The  ])ericementum  is  the  mutual 
periosteum  of  the  cementum  of  the  tooth  and  of  the  enclosing  alveolar 
wall ;  reflected  over  the  external  alveolar  wall  tliis  periosteum  becomes 
continuous  Avith  the  general  maxillary  periosteum.  In  addition,  the 
pericementum  is  the  ligament  binding  the  tooth  in  its  articular  (the 
alveolar)  walls.     As   a  periosteum   it  is  a   source  of  nutrition  to  the 

1  Black,  Ibid.  -  Dental  Cosmos,  vol.  xxxv. 


158  THE  SURGICAL  ANATOMY  OF  THE  TEETH. 

cementum  and  to  portions  of  the  alveolar  walls,  so  that  interference 
with  its  vascular  supply  is  followed  by  malnutrition  of  these  tissues, 
the  effects  being  governed  by  the  extent  of  the  interference  (see  General 
Pathology).  As  a  ligamentous  tissue,  its  fibres,  as  shown  by  Black,^ 
have  a  peculiar  arrangement.  The  bundles  of  fibrous  connective  tissue 
which  pass  from  the  alveolar  walls  to  the  cementum  are  oblique  in  their 
general  direction,  the  fibres  passing  from  a  point  nearer  the  margin  of 
the  alveolus  to  a  deeper  portion  of  the  root. 

The  nerves  of  the  pericementum  are  accustomed  to  a  degree  of  press- 
ure represented  in  the  amount  of  force  necessary  to  crush  the  particles 
of  food  ;  if  subjected  to  a  greater  stress,  they  rebel.^  Similarly,  if 
their  functional  activity  is  exalted  in  hypersemic  disturbances,  they 
become  cognizant  of  very  slight  pressures  and  react  more  strongly.  It 
is  to  be  remembered,  however,  that  the  teeth  rarely  receive  direct  stress, 
the  movements  of  the  teeth  in  mastication  being  more  of  a  rotary  and 
laterally  moving  character,  than  perpendicular. 

The  elasticity  of  the  pericementum  is  to  be  regarded  also  as  an  adju- 
vant to  the  local  circulation  ;  by  its  movements  the  blood  is  pumped 
through  the  vessels  of  the  part.  This  fact  becomes  important  when  it 
is  recognized  that  in  some  dentures  increasing  age  is  accompanied  by  a 
lessening  of  the  volume  and  elasticity  of  the  pericementum. 

The  power  of  recovery  of  the  pericementum  after  injury  appears  to 
be  very  great.  It  will  be  observed  that  the  pericementum  has  two 
sources  of  vascularity  :  one  from  the  apical  vessels,  that  from  which  the 
vascular  supply  of  the  pulp  arises ;  the  other,  an  anastomotic  circula- 
tion from  the  alveolar  walls,  directly  and  indirectly  from  the  general 
alveolar  periosteum.  When  the  apical  vessel-trunks  have  been  obliter- 
ated as  the  result  of  disease  the  pericementum  receives  from  the  anasto- 
motic circulation  a  blood-supply  practically  sufficient. 

The  cementum  maintains  its  vitality  so  long  as  the  pericementum  is 
intact;  in  the  condition  just  mentioned  it  is  evident  that  the  apical 
portion  of  the  cementum  dies,  or  is  at  best  very  ill  nourished.  The 
layer  of  cementoblasts  (osteogenetic  cells)  retain  their  function  so  long 
as  the  pericementum  is  intact,  and  under  varied  conditions  exert  their 
constructive  function  in  an  irregular  manner  (see  Hypercementosis). 

Surgical  Relations  of  the  Teeth. 

The  several  groups  of  teeth — incisors,  cuspids,  bicuspids,  and  molars 
— all  have  surgical  relationships  differing  in  each  jaw  and  in  each  dental 
group. 

^  Periosteum  and  Peridental  Membrane.  ^  Black,  Dental  Cosmos,  1895. 


SURGICAL  RELATIONS  OF  THE  TEETH. 


159 


Fig.  114. 


THE    LOWER    DENTURE. 

Incisors. — The  lower  central  incisors,  as  well  as  the  lateral  incisors 
and  cuspids,  receive  their  main  va.scular  supply  from  the  continuation 
of  the  inferior  dental  artery,  the  passageway  of  which  is  not  so  well 
marked  a  channel  as  in  the  portion  of  the  jaw  posterior  to  the  mental 
foramen.  The  neural  supply  is  from  the  inferior  dental  nerve,  which 
returns  through  the  mental  foramen  recurrent  branches,  which  pass  to 
the  muscles  about  the  mouth.  This  association  of  nerves  is  made  clini- 
cally evident  in  many  cases  where  dental  irritation  of  these  teeth  causes 
painful  symptoms  referred  to  the  soft  j^arts  about  the  mouth. 

Direct  surarical  interest  as  to  the  lower  incisors  associates  with  the 
relations  of  the  apices  of  the  roots  of  these  teeth  with  their  bony  sur- 
roundings. A  section  through  the  symphysis  of  the  jaw  will  show  the 
bone  to  be  very  dense  at  the  site  of  the  section.  Sections  passing 
throuo^h  the  axes  of  the  central  incisors 
will  show  that  beneath  the  apices  of 
the  roots  is  a  mass  of  irregularly  chan- 
nelled cancellated  bone,  bounded  by 
an  inner  and  an  outer  layer  of  corti- 
cal bone,  the  inner  or  lingual  layer 
being  much  more  dense  than  the  outer 
(Fig.  114).  As  a  rule,  the  nearest 
point  of  approach  pf  the  root  of  the 
tooth  to  the  surface  is  upon  the  outer 
or  labial  side,  where  but  a  thin  layer 
of  cortical  bone  may  overlie  the  apex 
of  the  root  in  the  incisor  fossa.  On  the 
lateral  incisors  the  layer  of  bone  is 
usually  a  little  thicker,  and  thicker  yet 
over  the  apex  of  the  root  of  the  cus- 
pid, provided  the  root  be  not  abnor- 
mally short.  In  all  of  these  teeth, 
and,  as  will  be  shown  later,  in  all  of 
the  lower  teeth,  the  minimum  thick- 
ness of  dense  cortical  bone  is  not  over  the  apices  of  the  roots,  as  in 
the  upper  jaw,  but  at  points  about  midway  between  the  necks  of  the 
teeth  and  the  root-apices.  This  will  explain  why  abscess  upon  the  roots 
of  the  lower  teeth  rarely  discharge  over  the  apices  of  the  roots  of  the 
teeth. 

Occasionally  the  roots  of  the  lower  incisors  are  overlaid  labially  by 
an  unusually  dense  layer  of  cortical  bone ;  this  fact,  taken  in  connec- 
tion with  the  observation   that  at  the   submental  portion   of  the  jaw, 


A  longitudinal  section   through  a  lower 
central  incisor  and  its  neighboring  parts. 


160 


THE  SURGICAL  ANAT02IY  OF  THE  TEETH. 


immediately  beneath  these  roots,  is  a  relatively  thin  layer  of  cortical 
bone,  furnishes  the  solution  as  to  why  an  abscess  upon  these  teeth  may 
open  beneath  the  chin. 

Bicuspids. — The  bone  overlying  the  roots  of  the  bicuspids  at  their 
lingual  aspects  is  sometimes  relatively  thin,  as  it  forms  the  wall  of  the 
sublingual  fossse.  Upon  the  labial  face  the  cortical  bone  is  in  greater 
amount,  although  thin.  The  spaces  between  the  first  and  second  bicus- 
pids usually  marks  a  site  immediately  above  the  mental  foramen,  al- 
though the  opening  may  be  posterior,  or  in  some  cases  anterior,  to  the 
position  named.  If  the  roots  of  the  bicuspids  are  abnormally  long, 
they  may  encroach  upon  the  area  of  the  foramen.  This  occurs  most 
frequently  with  the  root  of  the  second  bicuspid,  affections  of  which 
tooth  may  cause  diffused  pain,  apparently  owing  to  the  proximity  of  the 
root-apex  to  the  nerve-trunk  at  the  foramen. 

Molars. — In  studying  the  surgical  and  anatomical  relations  of  the 
lower  molars,  the  anatomical  subdivision  of  the  lower  jaw  becomes  most 
apparent  from  every  point  of  view.  It  is  anatomically  and  clinically 
divided  into  an  alveolar  portion  and  the  maxillary  portion  proper,  the 


Fig.  115. 


Showing  the  relations  of  the  roots  of  the  lower  third  molar  with  the  cavities  of  the  mouth  and 
neck,  and  with  the  external  bony  wall :  A,  cavity  of  mouth  separated  from  B,  the  cavity  of  the 
neck,  by  the  mylohyoid  muscles;  C,  base  of  the  coronoid  process ;  D,  muscles  of  the  cheek. 

alveolar  portion — that  portion  in  which  the  teeth  are  embedded  and 
which  surrounds  them — being  set  upon  and  inside  the  body  of  the 
bone.     The  fact  that  the  alveolar  portion  is  set  inside  the  body  division 


SURGICAL  RELATIONS  OF  THE  TEETH. 


161 


Fig.  116. 


is  not  so  apparent  in  the  anterior  portion  of  the  jaw,  although  it  will 
be  readily  seen  that  the  dental  arch  has  a  smaller  radius  than  the  max- 
illary ai'ch ;  but  at  its  extreme  posterior  portion  the  relationship  is  most 
evident,  where  the  outer  edge  of  the  eoronoid  process  is  some  distance 
external  to  the  buccal  faces  of  the  lower  third  mohr  (Figs.  115  and  116). 
It  is  with  this  superimposed  and  inserted  mass  of  bone  that  dental  dis- 
eases are  almost  entirely  concerned.  According  to  AUen,^  "  all  diseases 
affecting  this  portion  of  the  bone  are  to  be  regarded  as  dental." 

The  boundaries  of  the  molar  portion  of  the  alveolar  bone  are  to  be 
clearlv  kept  in  mind  (Fig.  116).  If  sawn  away  from  the  body  of  the  bone, 
it  will  have  the  form  of  an  irregular 
quadrangular  pyramid,  the  base  of 
which  represents  the  section  between 
the  first  molar  and  the  second  bicuspid, 
one  side  the  alveolar  margins  about 
the  molars,  another  the  buccal  por- 
tion of  the  bone  adjoining  the  exter- 
nal oblique  line,  its  inner  side,  the 
alveolar  portion,  having  the  inter- 
nal oblique  line  (mylohyoid  ridge) 
as  a  margin ;  its  remaining  side, 
the  bone,  overlying  the  inferior 
dental  canal.  These  four  sides 
merge  into  a  point  beyond  the  inner 
and  outer  divisions  of  the  base  of 
the  eoronoid  process.  In  position 
the  pyramid  lying  upon  one  side, 
that  forming  the  roof  of  the  inferior 
dental  canal,  is  seen  to  have  grad- 
ually altering  anatomical  relations 
advancing  toward  the  apex  of  the 
pyramid.  Viewed  upi^n  the  inside, 
one  edge  of  the  pyramid  lies  along  the  boundary  line,  the  internal  oblique 
line,  the  line  of  insertion  of  the  mylohyoid  muscle  Avhich  divides  the 
cavity  of  the  mouth  from  the  cavity  of  the  neck  ;  with  its  covering  of  mu- 
cous membrane  the  muscle  forms  the  greater  portion  of  the  floor  of  the 
mouth.  As  this  line  approaches  the  surface  of  the  mouth  progressively 
to  immediately  back  of  the  third  molar,  its  relations,  and  therefore  the 
relations  of  the  cavity  of  the  neck  to  the  roots  of  the  teeth,  also  change. 
So  that  while  the  roots  of  the  first  molar  are  rarely  deeper  than  the 
mylohyoid  ridge,  the  second  and  more  frequently  the  third  molar  roots 
may  pass  to  a  greater  depth  (Fig.  117).     It  will  also  be  observed  that 

^  Harrison  Allen.  Human  Anatomy. 
11 


Showing  the  relative  position  of  the  posterior 
portion  of  the  alveolar  boue  (the  deutale) 
with  the  maxilla  proper. 


162 


THE  SURGICAL  ANATOMY  OF  THE  TEETH. 


the  smaller  size  of  the  alveolar  arch,  as  -compared  with  the  mandibular 
arch,  causes  the  molar  portion  of  the  alveolar  bone  to  project  bodily 
into  the  cavity  of  the  mouth,  so  that  a  vertical  line  passed  through  the 


Fig.  117. 


Section  of  the  molar  teetti  and  corresponding  portion  of  the  inferior  maxilla ;  the  dotted  line 
represents  the  position  of  the  mylohyoid  ridge,  the  open  space  beneath  the  inferior  dental  canal. 

vertical  axis  of  the  third  molar  would  fall  directly  into  the  cavity  of 
the  neck  without  passing  through  the  body  of  the  bone  (see  Fig.  115). 
This  relationship  of  parts  makes  the  thinnest  portion  of  bone  over- 
Iving  the  roots  of  molars  at  the  apex  of  the  distal  root  of  the  third 
molar.  A  drill  passed  through  the  frequently  thin  covering  of  cor- 
tical bone  at  this  point  emerges  almost  exactly  in  the  groove  lodging 
the  mylohyoid  branches  of  the  inferior  maxillary  nerves  and  arteries. 
The  root  may  terminate  at  a  point  some  distance  behind  the  anterior 
pillar  of  the  fauces.  Upon  the  external  or  buccal  face  of  the  bone  it 
will  be  seen  that  the  position  of  the  third  molar  is  at  times  some  dis- 
tance posterior  to  the  outer  branch  of  the  corouoid  process,  the  con- 
tinuation of  the  external  oblique  line,  so  that  a  greater  distance  sepa- 
rates the  roots  of  the  second  and  third  molars  from  the  external  surface 
of  the  bone  than  with  any  of  the  teeth  of  a  denture.  Abscess  upon  the 
roots  of  particularly  the  lower  third  molar,  therefore,  finds  the  path  of 
least  resistance  as  to  pus-exit,  first,  by  destroying  the  pericementum  of 
the  tooth  and  finding  exit  at  the  gum-margin,  or,  if  the  outer  alveolar 
plate  is  not  entirely  walled  in  by  the  base  of  the  coronoid  process, 
through  the  alveolar  process  near  the  gum-margin  (Fig.  115).  An 
abscess  may,  by  penetrating  the  lingual  alveolar  wall,  open  far  back 


SURGICAL  RELATIONS  OF  THE  TEETH.  163 

ill  the  mouth,  if  the  roots  of  the  tooth  arc  not  cicopor  than  the  mylo- 
hyoid ridge  ;  if  the  roots  do  ])enetrate  beyond  this  ridge,  it  may  open 
in  the  neck  in  the  submaxiUary  triangle. 

In  some  cases  the  roots  of  the  second  and  third  molars  may  immedi- 
ately overlie  the  inferior  dental  canal,  instead  of  being  slightly  inward, 
and  the  tissue  intervening  between  the  apices  of  the  molar  roots  and  the 
canal  may  consist  of  the  very  thin  layer  of  perforated  cortical  bone 
Avhich  forms  the  roof  of  the  canal.  In  some  cases  a  molar  root  may  be 
so  deeply  embedded  as  to  encroach  upon  the  canal,  lessening  its  lumen 
and  causing  more  or  less  compression  of  the  inferior  dental  vessels  and 
nerves.  Pressure  from  sueli  sources  is,  no  doubt,  the  cause  of  obstinate 
maxillary  neuralgias,  which  would  be  greatly  exaggerated  in  disease- 
conditions  about  the  pericementum,  accompanied  by  inflammation  or 
even  hypertemia.  In  impacted  third  molars  the  pressure  of  some  part 
of  the  tooth  may  cause  great  distortion  of  the  course  of  the  canal 
(see  Chapter  X.).  The  anatomical  relations  of  the  third  lower  molars 
are  such  that  apical  abscess  upon  them  will  have  tardy  vent,  or  else  ojDen 
in  unusual  situation. 

The  blood-supply  to  the  inferior  maxilla  through  the  inferior  dental 
artery — large  single  trunks  which  traverse  the  bone  longitudinally  upon 
both  sides — may  be  seriously  impeded  or  checked  by  pressure  upon  the 
trunk  as  it  enters  or  shortly  after  its  entry  to  the  canal,  and  thus,  necro- 
sis of  half  the  maxilla  is  a  probable  danger.  In  many  cases,  however, 
w^iere  the  inferior  dental  vessels  have  been  obliterated  upon  one  side 
necrosis  does  not  occur,  the  anastomosis  of  the  facial  artery  wdth  the 
dental  about  the  mental  foramen  continuing  sufficient  circulation  to 
maintain  vitality. 

THE    UPPER    DENTURE. 

As  in  the  lower  jaw,  the  line  of  the  symphysis,  a  thickened  plane 
of  bone,  is  an  impediment  to  the  extension  of  disease  from  either 
side.  The  demarcation  between  alveolar  and  maxillary  portions  is  as 
clearly  defined  as  in  the  lower  jaw.  In  general  terms,  at  the  period 
of  maturity  a  plane  passing  through  the  floor  of  the  antrum  and  be- 
neath the  floor  of  the  nose  divides  the  alveolar  from  the  maxillary 
bone.  As  a  rule,  this  plane  would  also  rest  upon  about  the  height  of 
the  maxillary  vault.  In  general  character  and  in  both  vascular  and 
neural  supplies  the  upper  jaw  presents  features  differing  from  those 
in  the  lower  jaw. 

The  alveolar  bone  is  formed,  as  in  the  lower  jaw,  of  two  layers 
of  cortical  bone,  between  which  lies  cancellated  bone,  chambered  by 
the  several  alveoli  for  the  roots  of  the  teeth.  Of  these  two  plates, 
the  outer  is  the  thinner,  and,  unlike  the  outer  alveolar  boundary  of  the 


164  THE  SURGICAL  ANATOMY  OF  THE  TEETH 

lower   jaw,  is   of  nearly  uniform   thickness   over  the   roots   of  all  the 
teeth  (Fig.  118).     As  in  the  lower  jaw,  a  greater  thickness  of  bone 

Fig.  118. 


Section  of  an  upper  incisor  tooth,  its  attachments,  and  anatomical  relations. 

overlies  the  roots  at  their  lingual  aspects.  Differences  as  to  the  depth 
of  the  alveolar  process  are  more  apparent  in  the  upper  than  in  the  lower 
jaw,  measured,  first,  by  the  height  of  the  dental  vault,  and,  next,  by 
the  distance  from  the  occlusal  edges  of  the  teeth  to  the  reflection  of  the 
mucous  membrane  from  the  cheek  to  the  gums.  The  apices  of  the  roots 
of  the  several  teeth  in  the  upper  as  well  as  in  the  lower  jaw  are  usu- 
ally about  one-eighth  of  an  inch  or  more  above  the  line  of  reflection  of 
the  mucous  membrane.  The  common  vascular  trunk  from  which  the 
upper  teeth  derive  their  arterial  supply  is  a  short  branch  that  divides 
into  an  alveolar  portion  which  enters  the  posterior  wall  of  the  antrum ; 
running  in  the  muco-periosteum  of  that  sinus,  it  subdivides  into  numer- 
ous branches,  some  of  which  enter  the  alveolar  portion  of  the  bone  as 
posterior  dental  arteries  supplying  the  molar  and  bicuspid  teeth.  The 
posterior  buccal  portion  of  the  alveolar  walls,  with  the  overlying  gum- 
tissue,  are  supplied  from  the  same  source.  The  palatal  portion  of  the 
alveolar  process  is  supplied  by  a  separate  arterial  trunk,  the  descending 
palatine,  which  emerges  upon  the  palate  at  the  posterior  palatine  fora- 
men, running  forward  thence  to  anastomose  with  the  terminal  branches 
of  another  small  division  of  the  internal  maxillary  artery,  the  naso- 
palatine, at  the  incisive  foramen.  The  anterior  teeth  receive  their  vas- 
cular supply  from  the  second  branch  of  the  common  arterial  trunk, 
viz.,  the  infra-orbital  artery.  As  this  artery  runs  in  the  infra-orbital 
canal,  it  gives  off  descending  branches  which  penetrate  the  antrum  ; 
running  under  its  muco-periosteum,  it  supplies  the  anterior  portion  of 
the  sinus  and  branches  penetrate  the  bone  supplying  the  anterior  teeth, 
anastomosing  freely  with  the  posterior  dental  arteries. 


SURGICAL  RELATIONS  OF  THE  TEETH.  165 

Disease,  effusions,  etc.,  may  occlude  the  external  alveolar  arterial 
supply  and  cause  necrosis  of  the  dependent  })late  of  hone,  and  yet  the 
vascular  supply  of  the  internal  alveolar  ])late  remains  intact.  Aj^jain,  the 
external  alveolar  bone  overlying  the  anterior  teeth  may  suffer  occlusion 
of  its  circulation  without  affecting  the  posterior  external  alveolar  blood- 
sup})lv.  This  will  account  for  the  frequently  limited  character  of 
necrosis  of  the  upper  alveolar  bone,  as  compared  with  necrosis  occur- 
ring in  the  lower  jaw,  and  will  serve  to  explain  the  forms  of  sequestra 
in  certain  cases. 

The  neural  supply  to  the  upper  teeth,  derived  from  the  superior 
maxillary  division  of  the  trigeminus,  corresponds  almost  exactly  with 
their  arterial  supply.  The  complex  character  of  the  anastomoses  of 
the  dental  nerves  will  explain  in  some  measure  the  varied  character 
and  indefinite  location  of  pain  of  dental  source  in  the  upper  jaw. 

Central  Incisors. — The  surgical  relations  of  the  roots  of  the  central 
incisors  are  associated  with  the  floor  of  the  nose.  Recognizing  the 
bony  floor  of  the  nose  as  a  common  surface,  with  the  plane  of  bone 
forming  the  hard  palate,  and  the  teeth-bearing  bone  as  an  arch-shaped 
rampart  set  upon  this  plane,  it  will  be  seen  in  the  majority  of  cases 
that  the  roots  of  the  central  incisors  do  not  extend  deeper  than  the  base 
of  the  alveolar  bone  :  but  in  rare  cases  their  roots  may  impinge  upon 
the  bony  floor  of  the  nose,  and  a  very  thin  layer  composed  of  peri- 
cementum, bone,  and  muco-periosteum,  may  separate  the  apices  of  the 
roots  from  the  fioor  of  the  nose. 

In  some  cases  the  outer  alveolar  plate  overlying  the  apices  of  the 
roots  may  be  very  dense  and  comparatively  thick  ;  and  the  palatal 
alveolar  plate  be  thin,  and  furnish  the  line  of  least  resistance  to  pus- 
collections.  This  may  also  be  true  of  the  lateral  incisor ;  the  principal 
surgical  interest  of  which,  however,  lies  in  the  common  and  abrupt 
curvature  of  its  root-apex,  usually  pointing  away  from  the  median  line. 
It  is  of  interest  to  note  that  this  tooth  is  occasionally  not  found. 
Whether  the  lack  of  development  arises  from  no  cord  ever  being  given 
off  for  it,  or  whether  the  tooth -follicle  at  some  very  early  stage  suffered 
atrophic  changes,  is  not  precisely  known  ;  it  is  probable,  however,  that 
no  follicle  has  been  formed. 

Cuspids. — The  surgical  interest  as  to  the  cuspid  teeth  is,  first,  in 
their  very  deep  im])lantation,  in  many  cases  their  roots  extending 
beyond  the  nasal  floor,  but  to  its  outward  side ;  and,  next,  in  the 
unusually  compact  character  of  the  bone  overlying  their  roots.  Very 
frequently  the  bone  overlying  the  apex  of  the  root  is  of  extreme  thin- 
ness. 

Bicuspids. — The  first  bicuspid  is  chiefly  notable  for  its  tAVO  roots, 
labial  and  lingual.     When  these  roots  are  divergent,  which  as  a  rule  are 


166 


THE  SURGICAL  ANATOMY  OF  THE  TEETH. 


convergent,  the  palatal  root  may  be  overlaid  by  only  a  thin  layer  of 
tissues.  As  with  the  molars,  disease  may  attack  but  one  root  alone. 
With  the  second  bicuspid  an  additional  anatomical  relation  of  surgical 
interest  may  be  found.  The  root  of  this  tooth  may  underlie  the  floor 
of  the  anterior  portion  of  the  maxillary  sinus,  although  this  relationship 
is  not  so  common  as  with  the  next  tooth  in  the  dental  series.  It  is  to 
be  remembered,  as  shown  by  Cryer/  that  the  cavity  of  the  antrum 
becomes  larger  with  age ;  and  while  in  the  young  adult  the  roots  of  all 
of  the  posterior  teeth  may  be  separated  from  the  floor  of  the  antrum  by 
a  considerable  thickness  of  bone,  progressive  resorption  with  the  con- 
sequent enlargement  of  the  antral  cavity  may  carry  the  floor  of  the 
latter  not  only  down  to,  but  in  some  cases  beyond  the  apices  of  the 
roots  of  the  teeth  (Fig.  119). 


Fig.  119. 


0ms 


IstM 
0ms,  opening  maxillary  sinus ;  1st  M,  first  molar.    (Cryer.) 


It  will  be  observed  that  the  true  maxilla  begins  at  the  situation  of 
the  first  molar,  to  extend  outward  far  beyond  the  outer  alveolar  wall  as 
an  enormous  process,  the  malar  process,  which  is  but  a  shell  of  bone, 
forming  the  greater  portion  of  the  outer  wall  of  the  antrum.  While 
with  the  first  molar  usually  only  the  palatal  and  disto-buccal  roots 
underlie  the  antrum,  the  projection  of  the  malar  process  carries  the 
boundary  of  the  antrum  outwardly  beyond  all  of  the  roots  of  the 
second  and  third  molars.  Upon  lifting  the  lip  of  the  living  subject  the 
^  "Studies  of  the  Maxillary  Bones,"  Dental  Cosmos,  Jan.,  1896. 


THE  TEETH  AS  MECHANICAL  APPLIANCES.  167 

projection  of  the  malar  process  is  evident,  its  anterior  edge  overlying 
the  first  molar  tooth.  The  line  of  the  flot)r  of  the  antrum  usually  lies 
about  a  quarter  of  an  inch  above  the  reflection  of  the  mucous  membrane 
from  the  cheek  to  the  gum,  and  if  a  sharp  drill  be  passed  backward, 
upward,  and  inward  from  the  reflection  line  above  any  of  the  molars, 
the  antrum  is  readily  penetrated.  It  will  be  seen  that  the  anatomical 
relations  of  the  roots  of  the  molar  teeth  to  the  floor  of  the  antrum, 
particularly  in  mature  and  elderly  persons,  are  such  that  disease  of  the 
apical  pericementum  is  necessarily  followed  by  involvement  of  the  tis- 
sues of  the  floor  of  the  antrum.  Moreover,  extraction  of  teeth  in  some 
cases  would  be  inevitably  accompanied  by  fracture  of  the  bony  floor. 

The  apex  of  the  palatal  root  of  the  second  molar  lies  in  close  prox- 
imity to  the  groove  at  the  palatal  base  of  the  alveolar  process,  w'hich 
accommodates  the  posterior  palatine  artery,  so  that  slipping  of  an 
elevator  in  extraction  might  cause  injury  to  this  artery.  The  tuber- 
osity of  the  palatal  process  which  lodges  the  roots  of  the  third  molar  is 
a  loosely  cancellated  knob  of  bone,  having  but  weak  boundary  walls. 
At  the  base  of  its  palatal  portion  lies  the  posterior  palatine  foramen. 
The  frail  boundary  walls  have  been  broken  in  attempts  at  extraction  of 
this  tooth,  producing  fracture  of  the  condyloid  process.  Occasionally 
the  excavation  of  the  antrum  extends  far  into  this  tuberosity,  and 
forcible  attempts  at  extraction  of  a  conical  molar  have  resulted  in  driv- 
ing the  tooth  bodily  into  the  antrum. 

The  Teeth  as  Mechanical  Appliances. 

Having  studied  the  physiological  aspects  of  the  teeth,  they  are  to  be 
surveyed  as  mechanical  implements  in  which  derangements  of  the 
primary  mechanical  design  are  followed  by  morbid  alteration  in  dental 
physiology. 

The  teeth,  as  mechanical  instruments,  are  divided  into  four  well- 
recognized  anatomical  classes  :  incisors,  cuspids,  bicuspids,  and  molars  ; 
each  group,  and  indeed  each  member  of  each  group,  is  of  mechanical 
design  and  position  for  a  definite  office.  According  to  the  form  and 
position  of  a  tooth,  it  is  fitted  to  receive  and  resist  stress  applied  to  it. 
Stress  in  excess  of  this  amount,  or  received  from  an  abnormal  direction, 
is  to  be  regarded  as  a  menace  to  the  integrity  of  the  tooth.  The 
])articular  pathological  interest  in  an  excess  or  irregularity  of  stress  lies 
in  the  response  of  the  vital  parts  of  the  tooth  implicated.  The  tissue 
or  structure  mainly  concerned  in  the  vital  reactions  of  the  teeth  to^vard 
mechanical  overwork,  and,  contrawise,  toward  disuse  of  the  teeth,  is  the 
pericementum. 

The  eifects  of  overuse  and  of  disuse  will  be  discussed  in  detail  in  the 
section  dealing  Avith  diseases  of  the  pericementum. 


168 


THE  SURGICAL  ANATOMY  OF  THE  TEETH. 


THE  UPPER  DENTURE. 

Incisors. — The  broad  cutting-blade  of  the  central  incisors  receives 
a  stress  which  tends  to  force  it  directly  outward.  In  the  normal  den- 
ture this  stress  ceases  as  soon  as  the  posterior  teeth  are  brought  into 
occlusion.  The  length  of  time  the  stress  is  in  operation  depends  upon 
the  extent  to  which  the  upper  teeth  overlap  the  lower ;  if  the  overbite 
be  great,  the  stress  is  proportionately  increased.  The  roots  of  these  teeth 
have  as  a  mechanical  provision  against  the  stress  a  sectional  form 
resembling  a  scalene  triangle  having  much  rounded  angles,  whose  base 
is  parallel  with  the  edge  of  the  cutting-blade,  offering  a  broad  surface 
of  resistance.  The  tendency  of  the  force  of  mastication,  incision  in 
this  case,  tending  to  drive  the  teeth  away  from  the  median  line,  the  base 
of  the  triangle  is  placed  at  an  angle  with  a  plane  transverse  and  at  a 
right  angle  with  the  symphysis  (Fig.  121).  In  the  lateral  incisors  the 
same  provision  is  observed  as  to  the  arrangement  of  the  base  of  the 
section  triangle  of  the  root,  which  is  decidedly  more  scalene  (Fig.  122). 
While  it  would  be  apparently  more  in  harmony  with  anatomical 
design  that  the  length  of  the  root  should  correspond  with  the  amount 
of  stress  involved,  so  that  teeth  having  a  long  overbite  should  have  long 
roots,  no  such  rule  is  observable,  for  it  is  frequently  seen  that  teeth 
having  broad  and  long  cutting-blades  have  very  short  roots ;  but,  as  a 
rule,  the  broad  and  long  cutting-blade  is  associated  with  a  root  section 
triangle  having  a  broad  base. 

The  Cuspids, — To  appreciate  the  mechanical  design  of  the  cuspid 

Fig.  120. 


Side  view  of  the  cranium  of  a  tiger,  with  the  mouth  slightly  opened  to  show  the  relative  position 
of  the  great  canines.    (Tomes.) 

tooth,  it  must  be  studied  as  it  occurs  in  its  typical  form,  as  the  canine 
tooth  of  the  carnivora.  In  these  animals  the  enormously  developed  canine 
is  formed  to  serve  as  a  weapon  of  defence  and  offence,  being  provided  with 
a  very  extensive  and  deep  implantation  to  insure  strength  and  firmness  ; 
this  characteristic  is  a  constant  associate  of  the  true  canine.    In  the  preda- 


THE  TEETH  AS  3IECHANICAL  APPLIANCES. 


169 


tory  carnivora  tlie  upper  and  lower  canines  are  arranged  in  such  manner 
that  the  lower,  the  mandibular  canines,  lock  in  front  of  the  upper  ca- 
nines, so  that  any  substance  caught  Ijetween  them  is  firmly  held,  and 
it  is  necessary  to  tear  the  held  substance  to  free  it.  Bonwill  has  pointed 
out  another  function  for  these  teeth :  it  will  be  observed,  when  the  jaws 
of  an  animal  such  as  a  lion  or  tiger  are  wide  apart,  that  the  tips  of 
the  canines  upper  and  lower  are  in  contact  with  one  another,  the  lower 
in  front  and  outside  of  the  upper,  thus  the  lower  jaw  is  doubly  held. 


Fig.  121. 


Fig.  122. 


Fig.  123. 


Fig.  124. 


Fig.  125. 


Fig.  126. 


in  guides  (Fig.  120),  posteriorly  by  the  temporo-maxillary  articulation, 
anteriorly  by  the  cuspids  on  both  sides.  In  closing,  the  jaws  can  move 
in  but  one  position — that  which  will  bring  the  posterior  carnivoral  teeth 

exactly  in  the  relation  of  shear- 
blades  ;  the  canines,  therefore, 
guide  the  other  teeth  of  a  den- 
ture into  their  proper  occlusion. 
They  markedly  limit  the  lateral 
or  rotary  movement  of  the  jaws  ; 
so  that  in  the  human  denture  or  in 

Fig.  127. 


animals  where  the  rotary  movements  of  mastication  are  pronounced, 
the  canine  becomes  an  insignificant  tooth — it  is  reduced  to  an  in- 
cisor. The  tip  of  the  canine  cusp  in  man  is  occasionally  so  long  in 
those  dentures  having  a  long  overbite  that  its  office  as  a  guide  to  cor- 
rect occlusion  is  marked,  and  in  such  cases  the  prominent  canine  emi- 
nence overlying  the  length  of  the  cuspid  root  is  correspondingly  large. 
In  all  typical  hmnan  canines  or  cuspids  the  presence  of  the  double  cut- 
ting-blades at  an  angle  with  one  another  is  the  characteristic  feature  ;  as 
both  blades  are  functional,  the  tendency  of  the  root  of  this  tooth  is  to 


170  THE  SURGICAL  ANATOMY  OF  THE  TEETH. 

be  forced  directly  outward  (Fig.  123),  the  direction  of  the  resultant  of 
the  two  forces  received  by  the  blades  ;  the  stress  is  resisted  by  the  un- 
usual root  length  and  by  its  broadly  rounded  outer,  labial  wall,  and 
again  by  the  density  of  the  overlying  bone. 

The  Bicuspids, — Mechanically  the  human  premolars  (the  bicuspids) 
are  double  cuspids.  Reverting  to  the  function  of  the  preceding  classes 
of  teeth,  it  will  be  seen  that  the  incisors  incise  and  cut  oif  definitely 
sized  masses  of  food,  and  on  examining  the  nature  of  the  occlusion  of 
the  upper  cuspid  and  its  antagonists  it  will  be  seen  that  the  surfaces  are 
so  disposed  as  to  flatten  the  mass  previously  incised,  to  press  it  between 
four  surfaces.  The  double  cuspid  and  the  triple  cuspids  behind  them 
— the  upper  molars — are  so  formed  that  the  cutting-blades  of  the  outer 
or  buccal  sections  are  sharper  than  those  of  the  inner,  the  palatal,  or 
lingual  sections,  and  the  cusps  of  each  diminish  in  depth  progressively 
to  the  last  molar.  While  the  cutting-edges  of  the  molar-cusps  are 
fitted  for  cutting,  it  is  the  squeezing  surfaces  which  are  of  greatest 
functional  importance.  The  stress  upon  the  roots  of  these  teeth  is  in 
three  directions  :  outward,  when  the  buccal  cusps  are  in  action  ;  inward^ 
when  the  lingual  cusps  are  in  action,  and  there  is  a  constant  vertical 
stress  (Fig.  1 24).  The  roots  of  these  teeth  are,  therefore,  of  elliptical  sec- 
tion to  resist  the  inward  and  outward  strains  ;  and  cylindro-conical  ta 
resist  the  upward  stress.  These  facts  are  of  direct  clinical  importance  in 
the  restoration  of  lost  crowns  by  fillings  or  artificial  crowns,  for  if  the 
occlusal  surfaces  are  not  so  arranged  that  the  root  receives  stress  in  all 
of  these  directions,  and  all  stresses  are  not  properly  balanced,  overstrain 
or  disuse  of  some  portion  of  the  pericementum  follows.  This  applies 
also  to  the  incisor  teeth,  on  which  broad  surfaces  are  sometimes  added 
to  artificial  crowns  without  due  regard  to  the  distribution  of  stress  in 
other  parts  of  the  denture. 

The  first  upper  bicuspid,  having  deeper  cutting-blades  and  a  broader 
occlusal  surface,  requires  a  corresponding  increase  in  the  amount  of  root 
resistance  afforded ;  this  is  found  in  the  usual  bifurcation  of  the  roots 
of  these  teeth. 

The  Molars. — While  the  molars  receive  stress  laterally  upon  their 
outer  and  inner  cusp-sections,  the  greatest  stress  to  which  they  are 
exposed  is  nearly  vertical.  The  stress  outward  is  a  very  strong  one,  as 
affecting  the  roots  of  the  teeth,  mainly  because  of  the  increased  breadth 
of  the  tooth.  Pressure  upon  the  buccal  edges  operates  at  a  greater  dis- 
tance from  the  axes  of  the  teeth  than  in  the  bicuspids  :  hence  the  stress 
is  greater.  This  fact  is  of  clinical  importance  in  that  fillings  and  arti- 
ficial crowns  are  frequently  made  with  too  great  a  cusp  length,  thus 
increasing  the  stress  upon  the  buccal  roots.  It  will  be  seen  that  when 
the  palatal  cusps  of  the  molars  are  in  use  the  stress  received  by  them  is 


THE  TEETH  AS  MECHANICAL  APPLIANCES.  171 

usually  in  the  axis  of  the  palatal  root,  and  the  tendency  toward  dis- 
placement is  minimized  (Fig.  125). 

The  upper  third  molar  when  in  use  presents  a  cusp-arrangement 
interesting  when  the  nature  of  the  occlusion  is  studied.  The  usually 
single  palatal  occludes  with  the  broad  depression  between  the  cusps  of 
the  lower  third  molar  (Fig.  126).  The  mechanical  arrangement — a  dull 
conical  wedge  in  opposition  to  a  broad  basin — is  one  fitted  for  the 
crushing  of  hard  but  frangible  bodies  which  rest  in  the  basin  of  the 
lower  molar,  and  are  pressed  upon  by  the  wedge  of  the  upper  molar. 
A  given  amount  of  muscular  power  operates  at  this  point  with  the 
greatest  force,  because,  as  will  be  seen,  the  lower  jaw  is  a  lever  of  the 
third  class,  the  alveolar  bone  forming  its  long  arm,  so  that  the  further 
back  a  tooth  is  in  tlie  dental  series  the  greater  will  be  the  stress  with 
a  given  amount  of  muscular  power. 

The  tripod  disposition  of  the  roots  of  the  molar  teeth  is  in  corre- 
spondence with  the  stress  directions  upon  their  crowns  ;  the  rocking 
action  caused  by  the  outward,  inward,  forward,  and  backward  stresses  is 
fully  met  by  such  a  disposition  of  resistances.  These  movements,  great- 
est in  the  first  molars,  find  in  this  tooth  a  greater  root-divergence.  With 
a  lessening  of  the  lateral  stresses  in  the  hinder  teeth  there  is  a  lessened 
root-divergence  (Fig.  127),  until  with  the  third  molar,  where  the  stress 
is  mainly  vertical  the  roots  are  closely  placed  together,  and  the  stress 
of  direct  pressure  is  diffused  by  a  curving  backward  of  the  roots. 

In  the  foregoing,  as  in  the  succeeding,  remarks  it  is  fully  recognized 
that  during  the  period  of  the  development  of  the  teeth  and  jaws  and 
during  the  eruption  of  the  teeth  influences  are  at  work  which  may 
explain  many  of  the  anatomical  peculiarities  mentioned  and  cause 
variations  from  them,  yet  these  features  as  described  are  in  the  main 
characteristic  of  the  several  teeth. 

THE    LOWER    DENTUEE. 

Incisors. — The  stress  upon  the  lower  incisors  tends  to  force  them 
inward,  a  displacement  resisted  not  alone  by  the  angles  at  which  the 
elliptical  section  roots  are  set,  but  the  pressure  tends  to  close,  to  drive 
together  the  teeth  of  the  lower  incisive  arch  which  afford  mutual  su]> 
port  to  one  another  (Fig.  128).  The  broader  cutting-blade  of  the  lateral 
incisor  is  accompanied  by  an  increase  in  the  size  of  the  supporting  root. 
The  posterior  cutting-blade  of  the  lower  cuspid  is  the  longer,  and  it  is 
upon  this  blade  or  upon  its  outer  face  that  the  greatest  stress  is  received. 
Support  against  this  stress  is  afforded,  first,  by  the  incisive  arch,  and, 
secondly,  by  the  curvation  of  the  deeply  implanted  root. 

Bicuspids. — The  lower  bicuspids  are  not  truly  bicuspid,  the  first 
being  a  cuspid  with  a  partially  formed  second  cusp.     It  has  been  de- 


172 


THE  SURGICAL  ANATOMY  OF  THE  TEETH. 


monstrated  by  Bonwill  that  there  is  a  well-defined  anatomical  reason  why 
this  tooth  should  not  be  formed  as  the  upper  bicuspid — i.  e.,  the  inner  cusp 
would  be  a  constant  interference  Avith  the  cusps  of  the  occluding  teeth. 
It  will  be  noted  that  the  inward  inclination  which  the  buccal  wall  of 
this  tooth  has  in  common  with  the  buccal  walls  of  all  the  lower  pos- 
terior teeth  brings  the  axis  of  the  cusp  nearly  in  line  with  the  axis  of 


Fig.  128. 


Fig.  129. 


Fig.  130. 


the  root  (Fig.  129),  hence  the  tendency  to  lateral  displacement  is  neu- 
tralized ;  the  pressure  received  upon  the  lingual  surface  of  the  bicuspid 
is  antagonized  by  the  angle  at  which  the  axis  of  the  tooth  is  set  to  the 
perpendicular.  The  eight  anterior  lower  teeth  form  an  arch  against 
which  the  anterior  segment  of  the  tongue  exercises  pressure.  In  a  nor- 
mal denture  the  tendency  to  outward  displacement  which  would  arise 
in  consequence  of  this  pressure  is  prevented  by  the  upper  dental  arch 
mechanically  holding  the  lower  in  position.  When  the  teeth  of  the 
upper  arch  are  lost,  this  muscular  pressure  is  frequently  sufficient  to 
cause  outward  displacement  of  the  lower  incisors.  This  tendency  is 
more  pronounced  when  from  any  cause  the  attachment  of  the  lower 
incisors  is  lessened. 

The  crown  of  the  second  lower  bicuspid,  having  the  inner  cusp 
as  an  edge  rather  than  a  true  cuspid  section,  has  its  greatest  stress 
received  upon  the  buccal  cusp.  The  crown  of  this  tooth  is  bent  inward, 
so  that  its  buccal  cusp  lies  in  a  line  which  passes  through  the  axis  of 
the  root.  The  stress  is  in  two  main  directions,  inward  and  outward ; 
although,  as  in  all  of  the  posterior  teeth,  there  is  also  the  antero-pos- 
terior  stress.  In  all  of  the  lower  teeth  in  normal  occlusion  there  is  a 
tendency  to  mechanical  displacement  in  a  forward  direction,  which  be- 
comes usually  marked  when  the  loss  of  a  tooth  deprives  the  tooth  pos- 
terior to  it  of  its  anterior  support. 

Molars. — In  the  dental  segment  represented  by  the  second  bicuspid 
and  the  three  molars  Bonwill  has  pointed  out  that  the  buccal  cusps  are 
rounded  and  dull,  while  the  lingual  cusps  are  the  sharp  segments,  an 
arrangement  the  reverse   of  that   found   in   the  corresponding  upper 


THE  JAWS  AND  DENTURE  AS  A  MECHANICAL  APPARATUS.     173 

dental  segment.  The  greater  extent  of  pressure  upon  these  teeth  is 
received  upon  the  buccal  segments,  and  the  tendency  to  displacement  is 
therefore  inward  or  lingually. 


The  Jaws  and  Denture   as   a  Mechanical  Apparatus. 

Recognizing,  as  has  been  shown,  that  disarrangement  of  the  mechani- 
cal disposition  of  any  tooth  is  followed  by  an  alteration  of  the  local 
physiology,  the  principle  needs  elaboration  from  another  aspect — that  is, 
the  teeth  are  to  be  viewed  not  only  singly,  but  as  integral  parts  of  the 
entire  dental  system  ;  which  is,  first,  the  sum  of  the  single  teeth, 
together  with  the  mechanism  and  physiology  of  the  motor  appa- 
ratus. These  are  to  be  studied :  the  jaws  themselves  and  associated 
parts,  and  the  details  of  their  function. 

As  emphasized  by  Harrison  Allen,'  the  maxillary  bones,  particularly 
the  superior  maxillae,  although  in  close  relationship  with  the  cranial 
bones  enclosing  the  great  nervous  ganglia,  yet  belong  to  the  visceral 
skeleton  ;  -  they  are  but  attachments  to  the  neural  skeleton. 

The  teeth  are  arranged  and  are  contained  in  recesses  of  two  portions 
of  this  visceral  skeleton,  one,  a  fixed  or  immovable  mass  of  bone,  which 
has  a  definite  distribution  of  its  masses  fitted  to  aiford  great  resistance 
and  to  dissipate  force,  to  minimize  the  amount  of  shock  transmitted  to 
those  portions  of  the  neural  skeleton,  the  basal  cranial  bones,  which 

Fig.  131. 


Architectural  scheme  of  the  upper  jaw :  a,  nasal  column  ;  b,  malar  column  ;  e,  infra-orbital  arch  : 
d.  supra-orbital  arch  ;  e,  pterygoid  column  ;  /,  upper  nasal  half-arch  ;  g,  lower  nasal  half-arch  ; 
h,  maxillary  arch. 

enclose  the  brain-masses.  The  second,  a  movable  mass,  operating  from 
centres  which  are  in  apposition  with  the  brain-case  proper,  and  in  which 
another  mechanical  arrangement  dissipates  energy  transmitted  to  the 
areas  of  contact  between  the  visceral  and  neural  skeleton. 

A.  H.  Thompson,-^  enlarging  upon  Allen,  divides  the  disposition  of 

'  "Studies  of  the  Facial  Region,"  Dental  Cosmos,  1874. 

^  See  also  Hertwig's  Embryology.  ^  Dental  Cosmos,  1893. 


174  THE  SURGICAL  ANATOMY  OF  THE  TEETH. 

the  bone-masses  of  the  superior  maxilla  (Fig.  131)  into  columns  aiforcl- 
ing  resistance  to  the  force  received.  A  nasal  column,  its  axis  passing 
through  the  cuspid  tooth,  and  ascending  to  the  inner  margin  of  the 
orbit,  crossing  the  nasal  bone  at  an  angle  to  meet  a  corresponding 
extension  from  its  fellow  of  the  opposite  side.  A  second  column 
rising  perpendicularly  from  the  margins  meets  the  orbital  rim  at  its 
outer  side  ;  the  rim  of  the  orbit  furnishes  two  arches,  a  supra-  and 
an  infra-orbital  arch.  A  third  column  or  girder  passes  in  a  curved 
line  nearly  at  right  angles  with  the  other  columns.  "The  latter 
column  serves  to  brace  the  bone  against  the  lateral  stress  of  mastica- 
tion ;  the  other  columns  against  that  of  direct  occlusion."  "  The  loss 
of  the  cuspids  deprives  the  face  of  its  normal  fulness  due  to  the  canine 
column,  a  fulness  not  replaceable  by  mechanical  means."  Minor  braces 
may  be  outlined,  all  defending  the  maxilla  against  injury  from  the  forces 
received  by  it. 

The  greatest  force  of  impact  received  by  the  molar  teeth  is  by  the 
superior  maxillary  articulations,  dissipated  through  arches  and  projec- 
tions of  the  neural  skeleton,  so  that  concussion  of  the  cranial  contents  is 
reduced  to  its  lowest  limits. 

Examining  the  detached  inferior  maxilla,  it  will  be  seen  that  it  is 
also  provided  with  strengthening  columns  (Fig.   132),  which  protect 
it    from    injury   by   the    stress    received   upon    it.      The    mental   co- 
lumn, as  shown,  is  a  line  of  great  resist- 
F^^-  ^^2.  ance,  but  behind  it  the  point  of  emergence 

coRONo.D  FRoc.  Q^  ^l^g  mental  vessels  and  nerves,  the  men- 

/'/  ^.fe'ir      tal   foramen,  is  a  line    of  weakness,   pro- 
■\  i  I'lf         tected,  however,  by  the   usually  increased 
^pOQQ^^^=^Hl';''''''fi  thickness  of  the  cortical  bone  on  this  line. 

^A:^^^r^---^^'fl, Despite  this,  however,  a  perpendicular  line 

v^  // -^^^  passing  through  the  mental  foramen  repre- 

Architecturai  scheme  of  the  lower     gents  usually  the  line  of  least  resistance. 

jaw :    o,  mental  column ;  b,  coro-  m,       i  ^        ^  r>  xi  x  i         J 

noid  column;  c,  condyloid  col-  The  lateral  columns  ot  the  external  and 

umn;  d,  body  arch  or  curve;  e,     internal  obliquc    lines  are  the  columns  of 

arch  of  the  symphysis;  /,  molar  ^  •  i       i      i  i  i 

arch.  great  resistance   against   both   lateral  and 

direct  stresses.  The  condyloid  column  is  an 
efficient  brace  at  the  rear  edge.  It  is  found  with  some  degree  of  fre- 
quency that  these  columns  are  traversed  by  lines  of  lessened  resistance. 
A  constant  line  of  lessened  resistance  crosses  the  coronoid  and  condyloid 
columns  transversely  and  at  an  angle  on  a  line  above  the  attachment 
of  the  internal  pterygoid  muscle. 

As  tersely  stated  by  Thompson,  the  superior  maxilla  with  its  teeth 
represents  the  static  element  of  mastication  ;  the  inferior  maxilla  with 
its  teeth  and  its  attachments,  the  dynamic  element. 


THE  JAWS  AND  DENTURE  AS  A   MECHANICAL  APPARATUS      175 

The  lower  jaw  is  a  lever  of  the  third  elass  :  the  condyle  is  at  the 
fulcrum  ;  the  horizontal  distance  from  the  condyle  to  a  line  passing 
through  the  coronoid  process  and  tlie  angle  of  the  bone,  the  short  or 
power-arm  ;  from  the  condyle  to  the  mental  column  is  the  length  of  the 
long  or  weight-arm.  The  power  of  the  lever  is  represented  by  the 
action  of  the  temporal,  masseter,  and  of  the  pterygoid  muscles,  partic- 
ularly the  internal,  when  right  and  left  muscles  act  synchronously.  The 
weight  is  the  amount  of  pressure  brought  to  bear  upon  substances  be- 
tween the  teeth.  The  weight  upon  the  incisors,  these  teeth  being  at  the 
extremity  of  the  weight-arm,  is  less  in  amount  than  that  upon  teeth 
posterior  to  the  incisors ;  with  a  given  force  of  muscular  contraction, 
the  greatest  power  is  exercised  at  the  third  molars,  in  accordance  with 
the  mechanical  law  of 

W X  L  =  Fx  L'  or  Pxbc=  Wx  ca.    (See  Fig.  133.) 

Black  ^  records  the  amount  of  force  which  can  be  exerted  by  the 
jaws.     He  found  that  the  maximum  force  of  those  whose  jaw-power 

Fig.  133. 


was  tested,  to  be  175  pounds  on  incisors,  and  in  the  same  individual  240 
pounds  on  the  molars.  The  minimum  force  recorded  for  adults  was 
30  pounds  on  incisors  and  70  pounds  on  molars.  While  in  many  of 
the  cases  tested  the  ratio  between  the  force  exerted  through  the  incisors 
approximated  one-half  that  exerted  tlirough  the  molars,  which  corre- 
sponds quite  closely  with  the  mechanical  positions  occupied  by  incisors 
and  molars  on  the  mandibular  lever,  many  other  cases  showed  a  ratio 
of  1  to  3,  and  some  1  to  IJ.  These  discrepancies  occur  with  sufficient 
frequency  to  show  that  the  condition  of  the  pericementum  of  teeth  has 
more  to  do  with  the  force  exerted  upon  them  than  has  mechanical  posi- 
tion. With  an  average  distance  from  condyle  centre  to  the  cutting- 
edges  of  the  incisors  of  four  inches,  and  a  distance  from  condyle  centre 
to  the  axis  of  muscular  action  of  about  \\  inches,  when  a  force  of  100 
^  Dental  Cosmos,  June,  1895. 


176  THE  SURGICAL  ANATOMY  OF  THE  TEETH. 

pounds  is  brought  to  bear  upon  the  incisors  the  muscles  are  exerting  a 
contractile  force  of  266f  pounds. 

4  X  100  =  1|-  X  a;  =  l-i-  x  =  400     x  =  266f  pounds. 

The  amount  of  force  necessary  to  crush  food-stuflfe  by  direct  action 
ranges  from  30  pounds  for  tender  meats  to  90  pounds  for  tough,  fried 
meat ;  hard  crusts  resist  a  pressure  of  250  pounds ;  hard  candy 
requires  in  the  neighborhood  of  100  pounds.  The  stress  exerted  upon 
temporary  molars,  about  70  pounds,  is  quite  sufficient  to  crush  ordinary 
meats.  In  affections  of  the  pericementum  of  a  hypersemic  nature  the 
sensitivity  of  the  pericemental  nerves  is  much  increased,  so  that  less 
pressure  can  be  exerted  than  in  health.  According  to  the  investigator 
whose  work  is  quoted,  many  persons  involuntarily  fail  to  exert  sufficient 
masticatory  power  owing  to  the  debility  of  the  pericementum  of  one  or 
more  teeth. 

The  Dental  Mechanism. 

The  dental  apparatus  operating  upon  an  arm  of  a  lever  and  against 
a  fixed  base  has,  normally,  a  definite  arrangement  of  its  members, 
making  one  of  the  most  admirable  anatomical  structures  conceivable. 
Dentistry  is  indebted  to  W.  G.  A.  Bonwill,  of  Philadelphia,  for  the 
working  out  of  the  details  of  the  dental  mechanism.^ 

The  teeth  are  arranged  in  two  arches,  an  upper  and  a  lower,  the  upper 
being  the  larger  and  overlapping  the  lower  at  its  labial  and  buccal  as- 
pects. In  the  lingual  cavity  the  lower  arch  projects  beyond  the  upper. 
These  arches  are  usually  parabolic,  although  at  times  semi-elliptical, 
and  in  some  cases  the  dental  series,  upper  and  lower,  form  three  sides 
of  a  trapezoid  having  rounded  angles.  As  a  rule,  the  distance  from  the 
centre  of  one  condyle  to  the  mesio-occlusal  angles  of  the  lower  central 
incisors  is  about  four  inches,  which  is  also  the  distance  from  the  centre  of 
the  right  condyle  to  that  of  the  left,  lines  of  junction  through  these 
points  forming  an  equilateral  triangle.^  It  follows,  of  course,  that  in 
a  normal  denture  the  equilateral  triangle  is  also  to  be  included  in  the 
lines  joining  the  centres  of  the  glenoid  fossse  and  running  to  the  junc- 
tion of  the  upper  central  incisors. 

The  occlusal  surfaces  of  the  teeth  are  arranged  in  a  definite  manner. 
The  first  bicuspid  tooth  of  the  upper  jaw  is  the  anatomical  basis  from 

^  This  description  of  the  dental  mechanism  is  largely  derived  from  the  written  works 
and  personal  communications  of  Bonwill. 

^  In  Bonwill' s  written  communication  he  attaches  an  occult  significance  to  a  series  of 
measurements,  based  upon  the  equilateral  triangle  in  the  measurement  of  the  sizes  of  the 
teeth  and  the  determination  of  their  positions.  The  facts  cited  are  in  the  main  correct, 
but  are  not,  as  Bonwill  believes,  a  conclusive  argument  against  the  truth  of  organic 
evolution.  His  laws  are  as  all  anatomical  laws  subject  to  variation,  although  unusually 
constant. 


THE  DENTAL  MECHANISM. 


ni 


which  deductions  may  be  drawn  :  first,  the  d(K'per  the  cusps  of  this  tooth  ; 
for  the  character  and  depth  of  the  cusps  of  all  the  teetii  may  be  deter- 
mined by  an  examination  of  those  of  the  first  bicuspid,  the  more  the 
upper  teeth  overlap  the  lower,  the  overlapping  being  most  marked  in 
the  incisors,  and  least  with  the  third  molars  ;  secondly,  the  teeth  of  a 
denture  have  not  their  cusp-edges  on  a  plane ;  a  plane  surface  laid 
upon  teeth  is  in  contact  with  the  edges  of  the  central  incisors,  usually 
witli  the  cusj^ids,  bicuspids,  and  the  anterior  cusp  of  the  first  molars  :  the 
cusps  of  the  second  molar  are  at  a  distance  from  the  plane,  and  those  of 
the  third  molar  at  a  greater  distance — that  is,  the  line  of  the  molar  cusps 
curves  upward  (Fig.  134).     If  the  cusps  of  the  teeth  be  very  long,  the 

Fig.  134. 


Front  and  side  views  of  tl 


cuspids  may  sink  beneath  the  surface  of  a  plane  resting  upon  bicuspids 
and  incisors.  The  longer  the  cusps  the  more  pronounced  is  the  upward 
curve.  A  plane  laid  upon  the  lower  teeth  touches  the  occlusal  edges  of 
the  incisors,  cuspids,  and  only  the  distal  cusps  of  the  third  molar ;  the 
second  bicuspid,  first  and  second  molars,  are  below  the  plane,  the  first 
molar  farthest  below.  The  depth  of  this  depressed  curve  is,  as  in  the 
upper  teeth,  governed  by  the  length  of  the  cusps.  In  cases  where  the 
cusps  are  abraded  the  occlusal  surfaces  are  reduced  almost  but  not 
entirely  to  a  plane.  Thirdly,  it  will  be  observed  that  the  buccal 
cusps  of  the  teeth,  from  the  second  bicuspid  backward,  are  at  higher 
points  than  the  palatal  cusps,  so  that  if  a  curved  and  plastic  plane  be 
pressed  so  that  its  surface  is  in  contact  with  the  cusps  of  all  of  the  teeth 
of  one  side  it  will  assume  the  form  shown  in  Fig.  135.  The  longer  the 
cusps  of  the  teeth — /.  e.,  the  greater  the  overbite,  and  in  consequence 
the  greater  the  upward  curve  of  the  arch — the  more  the  surface  of  the 
plane  will  be  bent. 

12 


178 


THE  SURGICAL  ANATOMY  OF  THE  TEETH 


Placing  the  two  dental  arches  in  normal  relation  with  one  an- 
other, it  is  seen  that  each  tooth  (Fig.  134)  is  in  occlusal  contact 
with  two  teeth  of  the  opposite  jaw,  with  the  exception  of  the  lower 
central  incisors  and  the  upper  third  molars,  which  teeth  have  but  one 
antagonist.  The  interspace  between  any  two  teeth  of  either  jaw  passes 
nearly  through  the  vertical  axis  of  a  tooth  in  the  opposite  jaw.  The 
arrangement  is  such  that  should  a  tooth  be  lost,  its  occluding  teeth  still 
have  each  an  antagonist,  except  in  the  case  of  the  four  teeth  which  have 
but  a  single  antagonist.  Teeth  having  but  a  single  antagonist  are  lost 
through  a  process  of  gradual  extrusion  after  the  loss  of  their  antagonist. 

In  the  act  of  incising  food  the  jaws  are  first  separated  and  the  lower 
jaw  advanced  until  the  cutting-edges  of  the  upper  and  lower  incisors 

Fig.  135. 


The  horizon  of  the  line  of  occlusion  and  plane  of  occlusion. 


are  opposite  one  another.  While  the  jaws  are  in  this  position  with 
the  incisors  in  occlusal  contact  they  do  not  bear  alone  the  stress  of  what- 
ever muscular  force  is  applied,  but  it  will  be  seen  that  the  distal  cusps 
of  the  third  molars,  the  highest  points  of  the  lower  dental  arch,  advance 
and  meet  the  distal  cusps  of  the  upper  second  molars,  higher  points  of 
the  dental  arch,  so  that  when  the  incisors  are  in  edge-to-edge  occlusion, 
although  all  of  the  other  teeth  are  separated  to  an  extent  governed  by 
the  overbite,  the  dental  arch  is  supported  posteriorly  by  contact  of  the 
last  molars,  thus  preventing  undue  stress  upon  the  incisors.  As  the 
incisors  glide  past  one  another  the  lower  jaw  recedes,  and  an  increasing 
molar  area  comes  in  contact. 

The  teeth  of  man,  being  of  the  omnivorous  type,  adapted  both  for 
incising  and  grinding  food,  the  lateral  movement  of  the  jaws  is  of 
extreme  interest.     While  the  posterior  teeth  of  man,  notably  in  those 


THE  DEXTAL  MECHANISM.  179 

individuals  luivino;  lonir  eusjvs  to  their  teeth,  have  a  distinctly  carnivorous 
character,  yet  it  is  of  secondary  prominence  as  compared  with  the  her- 
bivorous character  of  the  molars. 

To  do  the  actual  work  of  the  mechanical  subdivision  of  food,  of 
course  the  cusps  and  molar  surfaces  of  the  teeth  must  be  in  effective 
contact.  After  a  mass  of  food  has  been  excised  by  the  incisors  and 
pressed  between  the  cus])ids  it  is  passed  to  the  posterior  teeth,  and  the 
lower  jaw  is  swung  toward  that  side,  when  it  is  seen  that  from  cuspid 
to  molar  the  rounded  buccal  cusps  of  the  lower  teeth  rise  until  they 
are  in  contact  with  the  sharp  buccal  cusps  of  the  upper  teeth.  Upon 
the  opposite  side  the  teeth  are  in  contact  at  two  or  more  points,  sup- 
porting the  arches  against  overstrain,  but  are  not  in  functional  use  ;  only 
one  side  of  the  jaw  is  in  functional  use  at  one  time,  the  food-masses 
being  shifted  from  side  to  side  until  mastication  is  completed. 

The  mechanism  for  the  proper  subdivision  of  the  food,  the  func- 
tion of  mastication,  being  as  described,  it  is  evident  that  aberrations  of 
tooth-arrangement,  the  loss  of  a  single  tooth  or  of  a  column  of  teeth,  will 
be  followed  by  a  corresponding  interference  with  mastication.  Aside  from 
the  Eesthetics  offended  by  the  abnormal  positions  of  teeth,  there  is  a  dis- 
tinct pathological  interest  involved  in  them,  as  shown  in  the  chapters 
on  Malpositions  of  the  Teeth  and  Diseases  of  the  Pericementum. 


CHAPTER   IX. 

DENTITION:  ITS  PROGHESS,  VARIATIONS,  AND  ATTENDANT 

DISORDERS. 

The  process  of  teething,  the  eruption  of  the  teeth,  technically  called 
the  process  of  dentition,  may  be  defined  as  the  vital  operations  through 
which  the  partially  formed  teeth  are  elevated  from  their  beds  in  the 
maxillae  until  the  gum  is  pierced  and  the  crowns  assume  their  ana- 
tomical positions  in  the  dental  arch.  It  includes  a  consideration 
of  the  completion  of  root-formation  and  the  coincident  development 
of  the  alveolar  walls.  It  is  evident,  therefore,  that  a  study  of  the 
process  of  dentition  is  a  continuation  to  the  study  of  dental  embry- 
ology ;  being,  in  fact,  the  later  stages  of  a  developmental  process  which 
began  in  the  sixth  week  of  embryonic  life  in  an  involution  of  the  epi- 
thelium upon  the  summits  of  the  jaws,  and  has  its  physiological  termina- 
tion in  the  apical  constriction  of  pulp-tissue  due  to  the  formation  of  the 
anatomical  apex  of  the  root.  Physiological  dentition  is  divided  into  two 
groups  :  first,  the  eruption  of  the  temporary  or  deciduous  teeth — first 
dentition  ;  secondly,  the  eruption  of  the  permanent  teeth — second 
dentition. 

Causes  of  Eruption. 

Explanations  as  to  why  teeth  erupt  are  unsatisfactory  and  many  of 
them  conflicting ;  none  which  has  been  advanced  is  sufficient  to  explain 
all  of  the  observed  phenomena.  Nearly  all  of  the  hypothetical  explana- 
tions advanced  may  be  included  in  two  classes — the  dynamic  and  the 
vital.  Those  who  subscribe  to  the  dynamic  view  hold  that  the  process 
of  dentition  is  due  to  the  pressure  of  the  forming  root  upon  the  tissues 
beneath  it,  causing  reciprocal  pressure  on  the  overlying  tissues  ;  resorp- 
tion of  the  latter  tissues  occurs  and  the  tooth-crown  emerges  through 
the  gum.  The  vital  theory  regards  eruption  as  a  physiological  pro- 
cess which  carries  the  developing  teeth,  practically  uninfluenced  by  the 
pressure-element,  into  their  positions  in  the  dental  arch.  The  prin- 
cipal objections  stated  to  the  dynamic  theory^  are  that  stunted  teeth 
erupt ;  that  is,  teeth  having  roots  so  short  that  downward  pressure  is 
insufficient  to  explain  their  emergence  in  the  dental  arch  are  found  in 
the  dental  arch  ;  and,  also,  that  the  distance  travelled  by  the  crown  of 
^  Tomes,  Dental  Anatomy,  fourth  ed. 
180 


PROCESS  OF  DENTITION. 


181 


a  tooth  in  the  process  of  eruption  is  greater  than  the  length  of  the  root. 
These  objections  arc,  however,  more  apparent  than  real ;  and  comparing 
the  observed  phenomena  with  the  dynamic  theory,  it  is  probable  that 
the  pressure  of  the  developing  root,  and  the  tissues  about  it,  are  at 
least  very  important  elements  in  the  process ;  and  yet  it  must  be  borne 
in  mind  that  the  changes  occurring  in  the  entire  mass  of  alveolar  bone 
are  as  marked  as  is  the  alteration  in  the  position  of  a  tooth  in  its  erup- 
tion.    The  alveolar  changes  do  not  cease  until  long  after  eruption. 

Process  of  Dentition. 

Dentition  may  be  said  to  begin  when  the  crown  of  the  tooth 
approaches  the  covering  of  the  bony  crypt  in  which  it  is  lodged  and 
resorption  of  the  edges  begins.  This  occurs  shortly  after  the  time  of 
beginning  root-formation.  The  relations  of  the  parts  at  this  period  are 
as  follows  :  each  tooth-follicle  is  lying  in  a  crypt  of  bone,  separated 
from  the  bony  walls  by  thick  layers  of  fibro-vascular  tissue  upon  all 
sides.  The  bone  of  the  floor  of  the  crypts  is  the  roof  of  the  inferior 
dental  canal  in  the  lower  jaw.  In  the  upper  jaw  the  floors  of  the  crypts 
are  not  far  beneath  the  level  of  the  infra-orbital  foramen,  from  which 
point  they  will  be  far  distant  in  the  mature  jaw.  The  crypts  are  almost 
roofed  by  the  bone  overlying  crowns,  although  a  fissure  exists  in  the 
roof  of  each  crypt  at  its  anterior  portion.  The  teeth  when  in  position 
will  have  their  necks  somewhat  beyond  the  site  of  these  fissures  ;  their 
roots,  still  unfijrmed,  will  extend  from  this  point  to  nearly  the  base  of 
the  existing  crypt,  and  instead  of  lying  loosely  in  their  roughly  spher- 
ical crypts,  the  future  roots  will  be  embraced  by  deposits  of  bone  sepa- 
rated from  the  roots  by  an  attenuated  portion  of  the  follicular  wall.  It 
will  be  seen,  therefore,  that  not  only  must  a  larger  deposit,  in  point  of 


Fig.  136. 


22  mouths  after  birth 
18  mouths  after  birth 

12  months  after  birth 


6  months  after  birth 


40th  week  (birth)   . 
30th  week  embryo  . 

18th  week  embryo  . 
17th  week  embryo  . 


Calcification  of  the  deciduous  teeth.    (Peirce.) 


length,  of  dentin  be  formed  than  in  the  crown,  but  bone  is  to  be  formed 
beneath  and  about  the  sides  of  this  root  sufficient  to  hold  firmly  the, 
at  present,  loosely  placed  tooth. 


182 


DENTITION. 


Whatever  the  cause,  as  soon  as  root-formation  begins  the  crown  of 
the  tooth  commences  its  journey  toward  the  gum-surface.  It  will  be 
observed  that  the  resorption  of  the  bony  impediment  to  the  advance  is 
upon  the  anterior  edge  (Fig.  QQ).  When  sufficient  of  the  bony  impedi- 
ment has  been  removed,  through  the  agency  of  osteoclasts,  to  permit  the 
passage  of  the  crown  of  the  teeth,  the  gum-tissue  is  next  resorbed,  until 
the  tip  of  the  crown  emerges  and  finally  takes  its  anatomical  position 
upon  the  summit  of  the  jaw.  The  time  at  which  this  occurs  differs 
with  the  classes  of  the  teeth.  As  has  been  said,  eruption  is  a  phase  of 
tooth-development  beginning  shortly  after  the  completion  of  the  crowns 
of  the  teeth,  and  it  has  been  seen  that  the  individual  teeth  differ  as  to 
the  extent  of  their  formation  at  a  given  time  (Figs.  136).      The  teeth 

Fig.  137. 


Deciduous  teeth.  Left  side. 


make  their  appearance   in  the  dental   arches  when   root-formation   is 
more  than  half  complete. 

Periods  of  Eruption. 

As  a  general  rule,  the  eruption  of  the  deciduous  teeth  may  be  said 
to  begin  about  the  seventh  month  after  birth,  and  is  completed  some- 
where about  the  twenty-fifth  month.  This  rule,  however,  varies  within 
wide  limits ;  some  children  may  be  born  with  teeth  erupted ;  there  are 
classical  examples  of  this  precocity — Ceesar  and  Richard  III.  ;^  again,  the 
initiation  of  the  process  may  not  occur  until  the  twelfth  month  or  even 
later. 

The  incisor  teeth  are  usually  erupted  in  pairs,  the  molars  and  cus- 
pids making  their  appearance  in  fours,  the  first  molars  in  one  group, 
the  cuspids  in  another,  and  the  second  molars  in  a  third  group.  The 
several  groups  require  different  lengths  of  time  to  complete  their  erup- 

^  York.  Marry,  they  say  my  uncle  grew  so  fast  that  he  could  gnaw  a  crust  at  two 
hours  old  ;  'Twas  full  two  years  ere  I  could  get  a  tooth.  Grandam,  this  would  have  been 
a  biting  jest.     Richard  III,  Act  II.,  Sc.  iv. 


SYMPTOMS  OF  DENTITION. 


183 


tion,  the  time  oceiipied  in  the  eruption  of  the  first  molars  being  longer 
than  that  required  for  the  eruption  of  the  other  groups.  Between  the 
appearance  of  additional  groups  of  the  teeth  an  interval  elapses,  no 
doubt  a  ])hysiological  provision,  for,  as  will  be  shown  later,  the  process 
of  dentition  is  usually  accompanied  by  evidences  of  more  or  less  local 
disturbance,  frequently  by  disturbances  throughout  the  intestinal  tract, 
and  even  reflex  disorders  of  the  central  nervous  system  occur.  It  is 
believed,  therefore,  that  the  period  which  elapses  between  the  eruption 
of  the  dental  groups  permits  the  organism  to  recover  from  the  effects 
of  previous  disturbance  before  the  new  source  of  irritation  appears. 

Table} 


Group  1.  Lower  central  incisors. 

Group  2.  Upper  central  and  lat- 
eral incisors. 

Group  3.  Lower  lateral  incisors. 

Group  4.  First  molars. 

Group  5.  Cuspidati. 

Group  6.  Second  molars. 


Time  of  eruption, 

7  months. 
Time  of  eruption, 

9  months. 
Time  of  eruption, 

12  months. 
Time  of  eruption, 

14  months. 
Time  of  eruption, 

18  months. 
Time  of  eruption, 

26  months. 


Duration  of  eruption, 

1  to  10  days. 
Duration  of  eruption, 

4  to  6  weeks. 


Interval,  2  to  3  mos. 
Interval,  2  months. 


Duration  of  eruption,    Interval,  4  to  5  mos. 

1  to  2  months.  j 

Duration  of  eruption,  ;  Interval,  3  to  5  mos. 

2  to  3  months. 
Duration  of  eruption, 

3  to  5  months. 


In  the  accompanying  table  it  will  be  noted  that  the  time  of  erup- 
tion of  the  lower  lateral  incisors  is  later  than  that  of  the  eruption  of  the 
upper  lateral  incisors.  The  reverse  course  is  frequently  observed  ;  in- 
deed, it  has  usually  been  accepted  as  the  rule  of  precedence  in  the 
United  States.  All  tables  as  to  periods  of  eruption  give  but  the  ap- 
proximate times ;  while  variations  are  extremely  common,  the  ages 
given  in  this  table  are  those  at  about  which  the  several  teeth  may  be 
expected  to  make  their  appearance.  Stellwagen  (the  American  editor 
of  Cokman),  in  commenting  upon  this  table,  states  that  the  periods  of 
eruption  in  this  country  are  from  one-seventh  or  more  earlier  than  the 
dates  given.  He  suggests  that  the  difference  in  food-habit  may  account 
for  the  differences  in  time. 

Pari  passu  with  the  development  and  eruption  of  the  teeth  are  devel- 
opmental changes  in  all  of  the  glandular  appendages  of  the  alimentary 
canal  in  such  wise  that  alterations  in  their  structure,  and  no  doubt  in 
their  physiological  chemistry,  are  accompanied  by  dental  provision  for 
the  mechanical  subdivision  of  foods  of  post-infantile  character. 


Symptoms  of  Dentition. 

The    process  of  dentition,   like    that   of  parturition,   although   un- 
questionably  a    physiological    one,    is    even    under    normal    conditions 

^  Coleman's  Dental  Surgery  (Stellwagen). 


184  DENTITION. 

attended  by  phenomena  which  would  usually  be  called  pathological. 
The  general  characteristic  of  all  physiological  processes  is  that  they  are 
carried  on  without  that  form  of  consciousness  of  the  individual  termed 
pain,  a  course  rarely  noted  in  either  parturition  or  dentition.  Within 
physiological  bounds,  therefore,  we  expect  evidences  of  local  disturb- 
ance as  an  essential  part  of  the  process  of  dentition.  These  are  of 
a  character  which  would  be  expected  from  a  survey  of  the  existing 
conditions.  The  erupting  teeth  are  exercising  pressure  upon  the  tissues 
which  overlie  them  and  a  process  of  resorption  of  these  tissues  is  in 
progress.  The  parts  about  the  tip  of  the  erupting  teeth  are  in  a  state 
of  irritation.  Normally  the  reaction  to  this  irritation  should  not  ex- 
ceed a  mild  active  hypersemia,  and  probably  there  is  a  causal  rela- 
tionship between  the  hypersemia  and  the  presence  of  the  cells,  caus- 
ing resorption  of  tissue.  The  vascular  reaction  is  evident  in  the 
usual  deepening  of  color  over  the  site  of  the  advancing  tooth,  and 
when  the  tip  of  the  latter  is  almost  visible,  being  overlaid  by  the  epi- 
thelium alone,  the  gum  beyond  the  tip  is  hypersemic.  The  temperature 
of  the  part  is  elevated.  As  in  all  hypersemic  conditions,  in  its  early 
stages  relief  is  afforded  from  the  irritation  by  pressure.  It  is  common  to 
find  the  infant  instinctively  seeking  relief  by  pressing  the  fingers  against 
the  gum,  and  its  mental  irritation  is  appeased  by  having  the  finger  of 
the  attendant  rubbed  upon  the  gum  over  the  advancing  tooth.  In 
the  same  manner  biting  npon  hard  substances,  such  as  teething-rings, 
aifords  relief.  Still  more  marked  is  the  soothing  effect  of  biting  upon 
cold  substances,  such  as  ice  which,  in  addition  to  mechanically  less- 
ening the  local  blood-supply,  causes  contraction  of  the  dilated  vessels. 
The  parts  about  the  erupting  tooth  give  every  evidence  of  being  in  a 
hypersensitive  condition,  not  alone  as  a  direct  consequence  of  the 
hypersemia,  but  also  from  direct  pressure  upon  nerve-filaments.  The 
evidences  of  nervous  disturbance  are  both  direct  and  indirect :  the 
direct  being  those  of  local  hypersesthesia ;  the  indirect  are  those  in- 
dicating reflex  disturbances,  the  most  constant  of  which  is  usually  a 
hypersecretion  of  saliva,  the  local  disturbance  reflexly  stimulating  the 
salivary  glands  to  increased  functional  activity.  Disturbances  of  the 
alimentary  canal,  while  common,  belong  to  pathological  rather  than  to 
physiological  dentition,  as  do  also  disturbances  of  the  central  nervous 
system. 

Prognosis  and  Treatment. 

Unless  the  process  of  dentition  be  accompanied  by  symptoms  of 
greater  severity  than  those  above  described,  it  will  go  through  its 
course  unaided,  and  calls  for  no  interference.  With  the  eruption  of 
the   molars   and   cuspids  the    irritation  will   be   exaggerated,  as  these 


PATHOLOGICAL  DEXTITIOX.  185 

teeth  are  usually  erupted  in  series  of  fours,  and  present  through  their 
forms  meehanical  obstructions  to  eruption.  While  normally  progress- 
ing dentition  calls  for  no  interference,  it  does  emphatically  demand 
that  precautions  be  taken  to  prevent  an  abnormal  (!Ourse.  The  in- 
fant must  be  properly  fed  and  nourished.  If  it  do  not  appear  to 
thrive  upon  the  food  it  is  receiving,  the  food  should  be  changed,  and 
if  necessary  again  changed  until  it  is  found  to  subserve  its  purpose — 
sufficient  nourishment.  The  question  and  problem  of  infant-feeding 
are  fully  discussed  in  works  upon  diseases  of  children,^  and  concern  the 
general  rather  than  the  dental  practitioner. 

It  is  of  the  utmost  importance  that  the  alimentary  canal  should  be 
kept  in  a  physiological  and  aseptic  condition.  Even  in  cases  where  den- 
tition appears  to  be  pursuing  a  regular  course  the  period  is  marked  by 
various  evidences  of  irritation  and  disordered  function  of  the  alimentary 
tract.  Although  there  is  not  in  all  cases  an  evident  causal  association 
of  teething  with  these  disturbances,  it  is  noted  clinically  that  the  symp- 
toms disappear  if  treatment  directed  to  oral  causes  be  pursued.  As- 
suming, as  is  warranted  by  evidence,  that  the  oral  condition  attendant 
upon  dentition  will  permit  the  growth  in  the  mouth  of  micro-organisms 
which  do  not  flourish  there  normally,  and  that  their  passage  into  the 
stomach  and  to  the  intestines  is  followed  by  various  fermentations — 
decompositions — the  products  of  which  act  as  local  and  in  some  cases 
general  irritants,  intoxicants,  or  poisons,  it  is  evident  that  the  removal 
of  the  morbid  conditions  of  the  mouth,  preventing  by  this  and  other 
means  the  development  of  organisms  in  the  mouth,  will  materially  lessen 
the  abdominal  symptoms.  It  is  found  clinically  that  antiseptic  treat- 
ment of  the  oral  cavity  is  followed  by  a  lessening  of  the  evidences 
of  intestinal  fermentation,  which,  of  course,  receive  appropriate  treat- 
ment also.  These  subjects,  however,  belong  to  pathological  dentition  ; 
but  presenting  as  minor  symptoms  during  the  course  of  apparently 
normal  dentition,  they  demand  and  must  receive  attention. 

A  normal  course  of  dentition  may  frequently  be  assured  by  proper 
precautions,  which,  if  not  taken,  will  be  followed  by  a  train  of  disorders, 
painful  and  uncomfortable,  if  not  dangerous. 

Pathological  Dentition. 

When  the  common  symptoms  noted  become  exaggerated  the  progress 
of  the  dentition  may  be  deemed  pathological. 

SYMPTOMS. 

The  symptoms  attendant  upon  pathological  dentition  cover  a  wide 
range,  beginning  as  evidences  of  pronounced  local  hypersemia,  with  all 
'  Starr,  Infant-feeding ;  J.  Lewis  Smith,  Diseases  of  Children. 


186  DENTITION. 

of  its  attendant  symptoms  and  consequences ;  the  other  extreme  is 
attended  by  profound  disturbance  of  the  central  nervous  system,  con- 
vulsions, coma,  and  death.  That  a  fatal  issue  should  follow  or  be 
consequent  upon  pathological  dentition  has  been  seriously  questioned  by 
most  authors  of  works  upon  diseases  of  children,  but  cases  have  been 
observed  wherein  no  other  sufficient  source  of  irritation  was  discover- 
able, and,  furthermore,  there  are  many  cases  on  record  where  appro- 
priate treatment  directed  to  the  dental  organs  has  been  followed  by  the 
disappearance  of  serious  disturbances  of  the  central  nervous  system. 

According  to  the  symptoms  observable,  which  may  furnish  the  only 
indication  of  the  pathological  conditions  present,  morbid  dentition 
may  be  classed  under  two  heads  :  first,  cases  in  which  all  disease- 
conditions  appear  to  be  local ;  secondly,  those  in  which  other  and  dis- 
tant organs  give  evidence  of  disorder.  These  may  again  be  subdivided 
according  to  the  severity  of  the  local  and  general  symptoms. 

Local  Symptoms. — Instead  of  the  normal  localized  hypersemia  of 
the  gum,  with  its  hypersensitivity  and  reflex  increase  of  secretion,, 
evidences  of  active  inflammation  may  be  observed :  the  gum  assumes 
a  dusky  hue ;  if  the  apex  of  the  tooth  be  about  to  penetrate  the  gum, 
the  epithelium  may  be  swollen  and  the  area  of  vascular  injection  be 
larger.  The  tissues  are  swollen,  the  temperature  is  elevated,  and  the 
child  gives  evidence  of  painful  local  disturbance,  notably  by  fret- 
ful crying,  and  by  seizing  the  breast  or  bottle-nipple  and  quickly 
releasing  it  as  soon  as  bitten  upon,  indicating  pain  upon  pressure. 
The  sleep  is  broken,  and  if  the  symptoms  continue  the  child  soon 
suflers  from  insufficient  nourishment.  The  readiness  with  which  the 
child  will  take  cold  substances,  ice  or  ice  water,  is  notable  and  self- 
explainable.  Pressure  and  rubbing  of  the  gum  at  a  point  distant  from 
the  focus  of  irritation  affi^rd  relief.  These  symptoms  usually  subside 
with  the  appearance  of  the  tooth  through  the  gum,  although  in  case  of 
erupting  cuspids  local  disturbances  frequently  persist  until  the  entire 
crown  is  erupted. 

In  the  more  marked  cases  of  local  disturbance  evidences  of  bacterial 
infection  of  the  mucous  membrane  of  the  mouth  make  their  appearance^ 
such  as  ulcerative  stomatitis ;  while,  as  a  rule,  the  breaking  down  and 
ulceration  of  the  tissue  are  confined  to  the  parts  overlying  the  erupting 
teeth,  a  general  stomatitis  or  widely  scattered  patches  of  ulceration 
may  make  their  appearance.  The  localized  condition  has  been  called 
odontitis  infantum. 

General  Symptoms. — Intestinal  Disturbances. — It  is  with  cases 
of  this  type  and  with  those  of  greater  severity  that  disorders  of  the  alimen- 
tary canal  are  commonly  associated.  These  may  express  themselves  in 
diarrhoea,  with  discharges  of  a  "  chopped  spinach  "  character,  in  a  serous 


PATHOLOGICAL  DENTITION.  187 

diarrhoea,  but  in  some  cases  obstinate  constipation  may  be  noted.  It 
is  the  rule,  even  in  the  milder  of  these  cases,  to  tind  the  stomach  reject 
food  immediately  or  soon  after  feeding.  In  the  diarrhceal  cases  excoria- 
tion of  the  anus  is  frequently  found,  indicating  the  irritating  nature  of 
the  alvine  discharges.  In  addition,  the  child  suffers  from  the  pains  of 
colic — /.  €.,  spasmodic  contraction  of  the  intestinal  muscles  and  the  gen- 
eration of  gases.  All  of  these  symptoms  clearly  point  to  abnormal 
fermentative  changes  occurring  in  the  contents  of  the  intestinal  canal, 
and  as  clearly  indicate  the  therapeutic  measures  likely  to  be  useful. 

Skin  Disorders. — It  is  so  common  as  to  be  almost  termed  the  rule 
to  find  at  the  time  of  these  intestinal  symptoms  that  there  are  eruptions 
observable  on  the  skin.  The  mildest  form  of  these  is  a  herpetic  erup- 
tion about  the  mouth  ;  in  other  cases  papular  and  vesicular  eruptions 
are  observed  upon  the  skin  of  the  body  and  limbs. 

PuL]\[ONARY  Symptoms. — The  close  association  of  the  fifth  and 
tenth  cranial  nerves  is  frequently  cited  in  dentistry,  notably  in  connec- 
tion with  shock  from  operations  ;  another  expression  of  it  may  be  noted 
in  the  laryngeal  cough  which  sometimes  attends  the  eruption  of  groups 
of  teeth,  and  which  disappears  upon  their  eruption. 

Nervous  Disorders. — Disorders  referable  to  the  central  nervous 
system  are  the  most  alarming,  and  are  those  indicating  the  higher 
grades  of  severity  of  irritation.  The  milder  forms  of  these  disturb- 
ances are  faint  muscular  twitchings.  The  child  wakes  out  of  sound 
slumber  with  an  irritable  cry,  and  is  soothed  with  the  utmost  difficulty ; 
it  dozes,  only  to  be  awakened  again.  In  these  cases  there  are  usually 
other  morbid  symptoms,  such  as  the  disturbances  of  the  alimentary  canal 
described  above  and  the  evidences  of  oral  affection.  These  sym])toms 
may  occur  without  any  such  evident  connection  with  the  teething-process 
that  a  probable  causative  association  with  dentition  is  not  made  out. 
In  fact,  in  the  absence  of  evident  local  irritation  the  association  of 
teething  with  the  general  disturbances  is  frequently  denied,  but  in 
refutation  of  such  a  position  it  is  noted  that  treatment  based  upon 
morbid  dentition  as  the  cause  of  the  nervous  disturbance  is  commonly 
followed  by  a  disappearance  of  the  latter.  There  is  much  doubt  as  to 
the  precise  nature  of  the  dental  irritation  in  such  cases,  as  there  is  no 
morbid  condition  of  the  parts  overlying  the  erupting  teeth  which  would 
serve  to  explain  the  irritation.  It  is  assumed  with  good  reason,  there- 
fore, that  the  irritation  is  of  the  pulp  itself;  that  the  tissue  of  the  pulp 
is  being  subjected  to  pressure  through  the  processes  of  tooth-building 
and  tissue-resorption  not  proceeding  harmoniously.  The  source  of  irri- 
tation has  been  by  some  authors  ascribed  to  an  inflammation  of  the 
follicle.  Certainly  such  an  inflammation  might  occur  in  the  tissues 
immediately  surrounding  the  tooth  ;  but  in  that  event  we  should  expect 


188  DENTITION. 

to  find  associated  disorder  of  the  overlying  tissues,  which  is  frequently 
not  the  case. 

A  distressing  symptom  not  easy  to  elicit  on  account  of  the  age  of 
the  patient  is  headache.  The  child  is  sleepless,  and  cries  without 
apparent  cause  ;  it  becomes  quiet,  partially  from  exhaustion,  and  after  a 
period  again  commences  sobbing.  The  indication  of  central  disturb- 
ance may  at  times  be  noted  in  the  contracted  pupils  of  the  eye  and 
in  throbbing  arteries.  The  usual  treatment,  the  administration  of 
chloral  hydrate  and  potassium  bromid,  with  cold  applications  to  the 
head,  furnishes  relief,  which  is  frequently  not  complete  without  atten- 
tion to  the  dental  organs. 

In  the  more  severe  and  dangerous  cases  the  evidences  of  disorder 
of  the  central  nervous  system  become  unmistakable.  These  appear 
as  clonic  convulsions  or  symptomatic  eclampsia.  While  it  is  probable 
in  many  cases  that  reflex  irritation  from  the  process  of  dentition  in 
itself  is  but  a  secondary  cause  of  convulsions,  yet  evidence  is  sufficient 
to  warrant  its  being  regarded  as  a  determining  factor.  In  very  many 
cases  teething-convulsions  appear  to  indicate  a  neurotic  family  taint, 
and  eclampsia  may  attend  many  disorders  in  children  of  this  type, 
notably  the  mechanical  and  chemical  irritation  induced  by  the  presence 
of  large  masses  of  indigestible  food  in  the  intestines. 

So-called  teething-convulsions  occur  usually  at  a  time  when  several 
— an  abnormal  number — teeth  are  in  process  of  simultaneous  eruption. 
The  onset  of  the  convulsions  is  rarely,  although  apparently  often, 
sudden.  If  the  child  be  closely  observed,  it  is  noted  that  a  period  of 
cerebral  disturbance^fretful  crying,  evidences  of  headache,  sleepless- 
ness, etc. — is  followed  by  a  period  of  dulness  and  somnolence,  or  the 
child  may  lie  with  eyes  half-open.  Twitching  of  one  or  more  groups 
of  muscles  may  be  observed ;  the  orbicularis  oris  and  other  muscles  of 
the  lips,  and  the  muscles  of  the  eye,  notably  the  superior  and  internal 
recti,  may  contract  spasmodically.  A  common  muscular  spasm  usher- 
ing in  convulsions  is  that  of  the  adductor  muscles  of  the  thumbs  ;  the 
thumbs  are  drawn  toward  the  palms  of  the  hands.  The  adductor  mus- 
cles of  the  feet  contracting,  the  feet  are  drawn  inward.  This  period 
may  be  ushered  in  by  a  sharp  cry,  the  eyes  roll  upward  with  the  lids 
half-open,  and  consciousness  is  lost.  The  symptoms  may  disappear,  the 
child  awakening  dazed  and  fretful ;  or  it  may  sink  into  sleep.  Unless 
the  source  of  irritation  be  removed,  or  active  therapeutic  measures  be  in- 
stituted, the  eclampsia  may  return  and  in  severe  cases  be  the  precursor  of 
death. 

TREATMENT    OF    PATHOLOGICAL    DENTITION. 

There  is  no  means  for  assuring  a  normal  and  smooth  progress  of 
dentition  comparable  in   value  Avith  hygienic  precautions.      If  intelli- 


PATHOLOGICAL  DEyTITIOS.  189 

gent  care  be  taken  of  the  clothing  and  diet  of  the  child,  together  with 
measures  to  insure  normal  digestion,  and  due  regard  be  paid  to  ventila- 
tion, in  the  vast  majority  of  cases  the  })eriod  of  dentition  will  be  passed 
through  with  l)ut  trivial  oral  disturbance.  In  all  cases  of  pathological 
dentition,  tlicretbre,  a  careful  superintendence  of  these  matters  must  form 
an  essential  feature  of  the  treatment  of  the  case. 

Treatment  of  Local  Disorders. — Since  conditions  of  hypersemia 
invite  the  development  of  micro-organisms,  it  is  evident  that  steriliza- 
tion of  the  mouth  must  play  an  important  part  in  the  treatment  of  the 
irritation  incident  to  teething.  The  importance  of  this  measure  is  fur- 
ther emphasized  by  the  researches  of  Miller/  who  found  that  numer- 
ous forms  of  organisms  associated  with  intestinal  fermentations  are  pres- 
ent in  the  mouth,  and  develop  when  conditions  favorable  to  their  groM'th 
apj)ear  ;  passing  into  the  alimentary  canal,  those  not  destroyed  by  the 
acid  gastric  juice  pass  into  the  intestines  and  give  rise  to  fermentations 
of  the  intestinal  contents. 

The  feeding-nipple,  which  should  be  of  the  simplest  type,  should  be 
well  washed  in  hot  water  after  each  use,  then  washed  in  a  dilute  anti- 
septic solution,  and  be  kept  submerged  in  it  until  needed.  Each  feed- 
ing-bottle should  be  sterilized  in  boiling  water  after  using.  The  practice 
of  the  nurse  rubbing  irritated  gums  with  the  finger  should  be  discoun- 
tenanced, as  should  also  the  use  of  teething-rings  which  are  permitted  to 
lie  about  and  take  up  infective  material.  If  hard-rubber,  ivory,  or 
metallic  rings  be  used,  they  should  be  carefully  sterilized  by  boiling. 

To  reduce  local  hyperemia  of  the  gum  above  an  erupting  tooth  a 
common  domestic  measure  is  valuable,  viz.,  a  small  block  of  ice  is 
placed  in  a  clean  napkm,  and  confined  in  place  by  a  knot ;  the  infant 
places  it  in  its  mouth  at  pleasure  if  old  enough,  or  the  nurse  permits 
the  child  to  bite  upon  it.  The  mechanical  effect  of  biting  upon  a  hard 
substance  has  added  to  it  a  degree  of  cold  which  lessens  the  local 
vascular  engorgement. 

It  should  be  noted  that  during  the  period  of  dentition  children  who 
are  vaccinated  against  smallpox  have  the  suifering  incidental  to  teething 
much  increased. 

More  marked  degrees  of  vascular  engorgement,  hence  irritation  and 
suffering,  usually  demand  the  relief  by  local  bloodletting  and  lessening 
mechanical  resistance  following  the  operation  of  gum-lancing  (see  later). 

Should  general  stomatitis,  with  or  Avithout  stomatitis  ulcerosa,  make 
its  appearance,  the  mouth  is  to  be  promptly  and  freely  sprayed  with  a 
3  per  cent,  solution  of  pyrozone,  followed  by  a  spray  of  potassic  chlor- 
ate, gr.  xx-sj,  which  usually  affords  prompt  relief.  Should  the  spots  of 
ulceration  not  disappear  promptly,  the  mouth  and  tissues  about  the 
^  Micro-organisms  of  the  Human  Mouth. 


190  DENTITION. 

ulcer  are  to  be  guarded  by  soft  linen  napkins ;  each  ulcer  is  dried  and 
touched  with  carbolic  acid,  full  strength.  The  spraying  is  to  be  re- 
peated at  intervals  of  three  hours  during  the  waking  period.  This 
method  of  treatment  is  productive  of  decidedly  better  results  than  fol- 
low the  use  of  the  common  formula  of  honey  and  borax. 

When  evidences  of  active  inflammation  exist  in  the  gum  overlying  an 
erupting  tooth  the  indication  is  free  gum-lancing  with  a  blade  of  such 
razor-like  sharpness  that  no  pressure  is  exercised  in  the  operation. 
Conjoined  with  this  measure,  to  which  is  added  spraying  with  pyrozone, 
steps  should  be  immediately  taken  to  empty  the  intestinal  canal  of  its 
contents,  as  not  infrequently  constipation  is  an  attendant  condition. 
The  constipation  incident  to  some  cases  of  stomatitis  or  gum  inflamma- 
tion (gingivitis)  may  be  induced  or  aggravated  by  the  administration 
of  soothing-syrups,  which  usually  contain  opium  in  some  form.  The 
same  result  is  produced  by  the  domestic  use  of  soothing-syrups  and 
paregoric  (tr.  opii  camphorata)  to  relieve  diarrhoea  ;  by  lessening  the 
sensitivity  of  the  bowel  and  decreasing  its  peristaltic  movements  irritat- 
ing substances  are  retained  in  the  bowel,  a  menace  to  the  child's  health. 
It  is  not  intimated  that  opium  in  minute  doses  (and  a  one-drop  dose  of 
tr.  opii  deodorata  is  a  very  large  one  for  an  infant  of  eight  or  ten 
months)  is  not  a  valuable  drug  under  some  conditions,  but  its  use  should 
follow  that  of  laxatives  and  intestinal  antiseptics,  not  precede  them. 

Treatment  of  Skin  Eruptions. — The  eruptions  which  appear  upon 
the  skin  during  dentition  may  be  a  source  of  annoyance  to  the  child  by 
causing  itching.  As  a  rule,  measures  directed  toward  a  regulation 
of  the  intestinal  functions  cause  a  disappearance  of  the  skin  aflections. 
If  the  eruption  be  widespread  and  cause  much  itching,  a  wash  of  phenol 
sodique,  diluted  to  one-third  with  water,  usually  aflbrds  relief.  If  the 
surfaces  be  then  dried  and  talc  powder  dusted  over  them,  the  condition 
is  much  alleviated.  About  the  mouth  and  over  excoriated  surfaces  an 
ointment  of  zinc  oxid  is  useful. 

Treatment  of  Intestinal  Symptoms, — These,  in  the  vast  majority 
of  cases,  call  for  two  measures — evacuation  and  the  use  of  antiseptics,  the 
character  of  both  evacuant  and  antiseptic  to  be  determined  by  the  nature 
of  the  case.  It  has  been  held  that  diarrhoea  during  dentition  is  due 
to  a  heightened  irritability  of  the  bowel,  a  reflex  irritation,  and  seda- 
tives have  been  administered  to  lessen  such  hypersensitivity.  That 
such  a  heightened  sensitivity  may  be  present  and  that  abnormal  progress 
of  dentition  may  produce  an  irritable  condition  throughout  the  intestinal 
tract,  are  quite  probable,  but  experience  has  shown,  and  modern  patho- 
logical theories  indicate  forcibly,  that  the  bowel-condition  is  caused  by 
the  action  of  irritating  products  of  fermentation  upon  the  walls  of  the 
intestine.     As    emphasizing  the    importance    of  pi'ompt   and   eiFective 


PATHOLOGICAL  DENTITION.  191 

thempeusis  in  this  connection,  it  mnst  be  remcmbcretl  that  not  only  are 
the  normal  intestinal  functions  interfered  with  as  a  consequence  of 
these  fermentations,  but  a  train  of  disturbances  follows.  First,  normal 
dio;estion,  both  gastric  and  intestinal,  is  incomplete  ;  instead  of  forming 
nutrient  solutions,  the  food  undergoes  abnormal  fermentations,  the 
products  of  which  act  as  local  poisons  disordering  the  function  of  the 
bowel.  Although  absorption  is  lessened,  it  does  not  cease,  and  poisonous 
substances  are  taken  into  the  portal  circulation.  There  is  no  doubt  that 
many  of  these  poisons  are  chemically  destroyed  in  the  liver,  but  some 
of  them  may  find  their  way  into  the  general  circulation  and  cause 
symptoms  of  toxsemia.  In  any  event,  the  formation  and  absorption  of 
assimilable  pabulum  are  greatly  lessened,  and  debility — /.  e.,  lessened 
vital  resistance — is  induced.  The  products  of  abnormal  fermentations 
act  as  local  irritants,  causing  irritation  of  localized  or  ^v^idcspread  areas 
of  the  intestine.  Concentrated  at  some  one  portion  of  the  length  of  the 
canal,  they  may  cause  spasmodic  contraction  of  its  muscular  wall,  the 
painful  condition  of  colic.  Other  fermentations,  or  the  same  perhaps 
acting  over  large  surfaces,  induce  irritative  diarrhoea.  So  long  as  these 
conditions  are  permitted  to  exist  all  bodily  functions  suifer,  and  if  denti- 
tion be  in  progress  its  course  is  interfered  with.  The  probable  causative 
connection  between  mouth  and  intestinal  fermentations  has  been  dis- 
cussed. 

Recognizing  the  cause  of  the  condition  in  the  presence  of  irritating 
substances  in  the  intestine,  the  rational  indication  is  to  free  the  bowel 
from  them.  There  is  perhaps  no  laxative  comparable  with  castor  oil 
for  this  purpose.  Children  take  castor  oil  better  than  adults.  After 
the  action  of  the  oil,  additional  fermentation  is  checked  by  the  use 
of  antiferments — antiseptics.  Preparations  of  thymol,  eucalyptus,  ben- 
zoic and  boric  acids,  such  as  listerine,  are  extremely  useful  in  this  con- 
nection ;  ten  drops  in  water  may  be  administered  every  three  hours. 
Both  powders  and  solutions  given  to  children  may  be  sweetened  by  the 
addition  of  a  minute  quantity  of  saccharin,  which  has  the  additional 
advantage  of  being  an  intestinal  antiseptic.  The  subsequent  adminis- 
tration of  magnesium  hydrate  is  useful ;  it  has  the  advantage  of  allaying 
irritation  by  coating  the  mucous  membrane  ;  and  if  acids  be  present, 
they  combine  with  the  magnesium,  forming  faintly  laxative  salts.  To 
lessen  great  irritability  and  procure  quiet  a  few  drops  of  paregoric  may 
be  added  to  the  magnesium  fluid.  Compound  chalk  powder — mist, 
pulv.  cretae  co. — is  also  used  for  this  purpose. 

Treatment  of  Nervous  Conditions.  —  Should  the  premonitory 
symptoms  of  disturbance  of  the  nervous  system  make  their  appear- 
ance, attention  should  at  once  be  directed  to  a  search  for  the  cause.  If 
constipation  exists,  the   bowels  should  be  freely  opened  ;    magnesium 


1 92  DENTITION. 

citrate  in  efFervescing  solution  is  well  taken.  Clothing  is  loosened,  cold 
applied  to  the  head,  and  an  examination  of  the  gums  made.  If  a 
tooth,  or,  as  is  more  frequently  the  case,  several  teeth  are  in  process  of 
eruption  at  one  time,  their  crowns  partially  or  completely  imprisoned  by 
overlying  gum,  lancing  should  be  done  at  once.  More  severe  symp- 
toms call  for  more  active  treatment,  the  general  therapeutic  principle 
involved  being  the  lessening  of  the  cerebral  blood-supply.  This  is 
most  quickly  accomplished  by  23lacing  the  child  almost  Avaist-deep  in 
water  as  hot  as  can  be  borne  and  pouring  cool  water  over  the  head, 
when,  as  a  rule,  the  symptoms  promptly  subside.  After  immersion,  a 
rectal  injection  of  glycerin  (one  drachm)  will  usually  cause  a  free  stool. 
To  insure  a  period  of  cerebral  quiet  it  is  advisable  in  the  more  severe 
cases  to  administer  a  cerebral  sedative,  a  bromid  preferably,  which,  if 
combined  with  chloral  hydrate,  which  children  bear  well,  will  induce 
sleep  : 

]^.  Chloral,  hydrat.,  gr.  ij  ; 

Sodii  brom.,  gr.  v  ; 

Starch  paste,  lij. — M.  (Atkinson.) 

S.  To  be  administered  per  rectum. 

After  sleep,  if  appearances  indicating  dental  irritation  be  observed, 
gum-lancing  is  practised. 

It  has  been  repeatedly  noted  that  where  evidence  of  marked  cerebro- 
spinal irritation  is  present,  for  which  no  probable  source  can  be 
assigned  and  an  examination  of  the  gums  shows  no  apparent  local 
disturbance,  yet  if  it  be  at  a  period  when  one  or  more  teeth  are  in 
process  of  eruption,  but  are  still  covered  or  bound  down  by  gum-tissue, 
if  gum-lancing  be  practised,  relief  is  immediate  and  may  even  avert 
a  threatened  attack  of  eclampsia.  It  is  presumed  that  these  are 
cases  of  pulp-irritation  in  which  a  failure  to  sufficiently  remove  tissue 
in  advance  of  the  tooth-crown  has  caused  pressure  upon  the  pulp  from 
below. 

Gum-lancing. — The  operation  of  gum-lancing  consists  in  making 
incisions  through  the  gum-tissue  overlying  developing  teeth  in  such 
manner  as  to  remove  mechanical  obstruction  to  their  advancement. 
The  direction  and  character  of  the  incisions  are  governed  by  the  form 
of  the  advancing  tooth  (Fig.  138). 

The  gum  over  the  incisors  and  cuspids  is  divided  on  a  line  parallel 
with  the  cutting-edges  of  the  teeth  ;  the  cut  over  the  upper  incisors 
should  be  a  little  outside  of  the  teeth-edges;  that  over  the  lower 
incisors  slightly  inside,  so  as  to  induce  normal  positions,  the  upper 
teeth  outside  of  the  lower. 

When  the  point  of  the  cuspid  has  penetrated  the  gum-tissue  the 


PATHOLOGICAL  DENTITION.  193 

crown  is  still  confiueJ,  owing  to  the  conical  form  of  the  tooth,  so 
that  to  effectually  free  it  radial  cuts  may  be  necessary  [C,  Fig.  138). 
The  gum  over  the  molars,  with  the  exception  of  the  upper  first,  is 
divided  in  X-form,  the  cuts  extending  from  cusp  to  cusp.     The  upper 

Fig.  138. 


Lines  of  incision  in  lancing:  A,  A,  over  the  molars ;  B,  B,  over  the  cuspids  and  incisors  before 
eruption :  C,  C,  over  the  molars  and  cuspids  after  partial  eruption. 

first  molar  having  but  faintly  marked  cusps,  and  only  an  outer  and 
inner  cutting-edge  to  the  tooth,  is  best  freed  by  a  crucial  incision. 

The  instrument  to  be  used  for  dividing  the  gum  is  a  pointed  bis- 
toury of  extreme  sharpness  ;  its  edge  is  to  be  wrapped  in  linen  or  cord 
until  only  a  half  inch  from  the  point  is  exposed.  This  precaution  is 
taken  to  avoid  accidental  wounding  of  the  mouth.  The  child  is  to  be 
placed  and  held  in  such  position  that  the  light  shall  fall  upon  the  jaw 
to  be  operated  upon,  and  so  that  no  movements  shall  be  permitted.  It 
is  advisable — almost  necessary — to  have  an  assistant  hold  the  child  in 
the  proper  position  so  that  it  cannot  move  head,  body,  or  limbs.  A 
position  favorable  for  operating  is  to  have  the  child  lie  upon  its  back 
between  the  knees  of  an  assistant,  the  left  hand  of  the  assistant  holding 
the  hands  of  the  infant,  the  right  hand  being  used  to  steady  the  head. 
In  another  position  the  child  sits  upon  one  thigh  of  the  assistant,  the 
back  of  the  head  resting  upon  the  chest,  and  the  hand  of  that  side 
(usually  the  right)  pressed  upon  the  child's  forehead  to  hold  the  head 
firmly.  The  other  hand  and  forearm  hold  the  child's  arms  and  hands 
firmly. 

The  operator  encloses  the  gum  about  the  part  to  be  cut  with  the 
thumb  and  forefinger  of  the  left  hand,  so  that  the  bistoury  cannot  slip 
and  cut  lip,  cheek,  or  tongue,  Incision  over  the  erupting  tooth 
should  be  made  until  the  knife-blade  is  felt  to  touch  the  enamel- 
surface.  The  operation  of  scarifying  the  gums,  making  merely  a  few 
scratches  to  relieve  engorged  vessels,  is  but  temporizing  with  the  condi- 
tion ;  the  cut  should  be  of  sufficient  extent  to  entirely  remove  tension 
from  above  the  tooth.  The  little  finger  of  the  right  hand  may  rest  upon 
the  chin  of  the  child  as  an  additional  guard. 

13 


194  DENTITION. 

In  case  the  crown  of  an  erupting  molar  is  confined  by  a  block  of 
tense  gum  attached  upon  two  or  more  sides,  the  entire  block  is  to  be 
removed ;  the  block  is  drawn  tense  by  means  of  traction  with  a  tenacu- 
lum piercing  the  flap,  and  three  sides  freed  by  means  of  the  bistoury 
point ;  the  final  cut  may  be  made  with  scissors  of  extreme  sharpness. 

While  it  is  true  that  in  many  cases  children  struggle  under  this 
operation,  and  give  evidence  that  it  is  a  painful  procedure,  gum-lancing 
is  frequently  followed  by  immediate  tranquillity  upon  the  part  of  the 
child ;  fretfulness  disappears  and  nursing  is  resumed  immediately  after 
the  operation,  which  occupies  but  a  few  seconds  of  time. 

More  or  less  bleeding  follows  upon  the  operation,  which,  as  a  rule, 
ceases  spontaneously.  A  short  period  of  bleeding  is  desirable,  so  that 
vascular  engorgement  may  be  reduced.  Suckling  by  the  infant  usually 
serves  to  check  the  bleeding ;  the  tissues  about  the  cut  surfaces  are  com- 
pressed by  tongue  and  lips  during  suckling,  and  bleeding  ceases.  In 
the  event  of  the  bleeding  continuing  the  mouth  should  be  carefully  ex- 
amined, and  a  piece  of  ice  in  a  napkin  may  be  given  the  child  to  suck. 
Obstinate  bleeding  may  require  the  use  of  styptics,  but  these  should  be 
of  a  character  to  cause  only  coagulation  of  the  blood,  not  the  destruction 
of  tissue.  A  little  powdered  tannin  laid  upon  the  cut  acts  promptly,  as 
does  also  a  small  amount  of  powdered  alum. 

CONSTITUTIONAL   STATES   MODIFYING   DENTITION. 

Children  who  are  the  victims  of  hereditary  syphilis  usually  cut  their 
teeth  very  early,  the  alveolar  process  being  in  many  cases  insufficient. 
Cases  are  recorded  where  children  have  been  born  with  crowns  of  teeth 
visible  upon  the  gum,  there  being  no  evidence  of  root-formation,  the 
crowns  being  loosely  held  to  the  gum  by  fibrous  tissue.  It  is  necessary  to 
remove  these  loose  crowns  to  permit  the  infant  to  suckle.  Children 
aifected  with  rachitis  have  the  process  of  eruption  much  delayed.  It  is 
seen,  therefore,  that  the  presence  of  loose  crowns  of  teeth  is  a  condition 
pointing  to,  though  by  no  means  diagnostic  of,  hereditary  syphilis.  Also, 
that  long-delayed  eruption  of  teeth  should  prompt  a  search  for  further 
indications  of  rachitis.  Particularly  in  children  in  whom  a  history  of 
hereditary  syphilis  is  obtainable  the  process  of  dentition  may  be  accom- 
panied by  rapid  and  frequently  widespread  breaking  down  of  the  soft 
tissues  over  and  about  erupting  teeth.  Local  measures  of  treatment 
seem  to  be  of  but  little  avail,  except  that  antiseptic  treatment  un- 
doubtedly prevents  complications  from  extraneous  infection. 

In  children  classified  indefinitely  as  strumous,  which  may  mean  the 
children  of  syphilitic  or  tuberculous  parents,  or  those  with  no  such 
history  whose  surroundings  are  of  the  most  unhygienic  kind,  the  process 
of  dentition  may  not  only  have  an  untoward  course,  but  phagedenic 


SECOND  DENTITION.  195 

ulcerations  may  occur.  It  is  usually  in  the  degree  of  a  child's  debility, 
either  inherited  or  acquired  through  improper  care,  that  dentition 
assumes  morbid  features.  The  treatment  of  such  cases  must  be  di- 
rected to  raising  the  health  standard.  As  local  therapeusis,  no  meas- 
ures seem  more  effective  than  the  sprays  of  hydrogen  dioxid  first ; 
next,  potassium  chlorate,  and,  if  conditions  indicate  it,  sprays  of 
dilute  listerine,  which  is  stimulant,  antiseptic,  and  slightly  astringent. 
Infantile  Scurvy. — Cases  are  recorded^  in  which  the  improper 
feeding  of  children  has  been  followed  by  evidences  of  scorbutus.  The 
gums  become  tumid,  and  hemorrhagic  extravasations  occur  in  their  sub- 
stance ;  the  periosteum  is  stripped  from  the  margins  of  the  alveolar 
walls,  the  soft  tissues  hanging  in  discolored  pendulous  masses  about 
and  beyond  the  teeth  if  any  be  erupted.  Local  treatment  proving 
ineffective,  the  scorbutic  nature  of  at  least  one  of  these  cases  was  made 
clear  by  the  disappearance  of  the  oral  disorder  when  the  patient  "vvas 
placed  upon  an  antiscorbutic  diet. 

Second  Dentition. 

The  period  of  second  dentition  begins  without  disturbance  of  the 
temporary  denture,  by  the  eruption  of  the  first  permanent  molars,  pos- 
terior to  the  second  temporary  molars.  At  the  period  when  this  occurs, 
from  five  to  seven  years,  all  of  the  permanent  teeth  are  in  process  of 
formation,  even  the  third  permanent  molars,  although  none  other  of 
the  permanent  teeth  except  the  first  molars  will  normally  appear  in  the 
dental  arch  for  a  year,  or  in  some  cases  two  years.  The  order  in  which 
the  permanent  teeth  make  their  appearance  varies,  but  the  following 
table  shows  the  approximate  dates  at  which  they  may  be  expected  to 
appear  in  the  dental  arch  : 


First  Molars, 

51- 

-  7; 

vears. 

Central  Incisors, 

7  ■ 

-  s" 

Lateral  Incisors, 

8  . 

-  9 

First  Bicuspids, 

10 

-11 

Second  Bicuspids, 

11 

-12 

Cuspids, 

12 

-14 

Second  Molars, 

12 

-15 

Third  Molars, 

16 

-20 

and  indefinitely  beyond. 

With  the  exception  of  the  permanent  molars,  all  of  the  teeth 
have  deciduous  predecessors,  the  bicuspids  being  the  successors  of 
the  temporary  molars. 

At  the  time  of  eruption  of  the  first  permanent  molars  calcification 
^  E.  C.  Kii-k,  Pruc.  Odontological  Society,  New  York,  Dental  Cosmos,  1895. 


196 


DENTITION. 


has  been  for  some  time  complete  in  the  roots  and  alveolar  process  about 
the  roots  of  the  temporary  teeth,  and  the  roots  of  the  deciduous  in- 

^  .  cisors  are  already  beginning  to  be 
absorbed,  ijari  passu  with  the  de- 
velopment of  the  corresponding- 
permanent  teeth.  The  permanent 
teeth  are  all  at  different  periods  of 
formation,  diifering  in  extent  ac- 
cording to  groups  of  fours  :  (1)  cen- 
tral incisors,  (2)  lateral  incisors, 
(3)  first  and  (4)  second  bicuspids, 
(5)  cuspids,  (6)  second  molars,  (7) 
third  molars — group  (1)  being  the 
first  molars  (Fig.  139).  The  figure 
exhibits  the  stage  of  tooth-forma- 
tion— i.  e.,  the  extent  of  calcifi- 
cation at  successive  periods.  As 
calcification  proceeds  in  the  per- 
manent teeth  having  deciduous  pre- 
decessors the  latter  suffer,  first, 
loss  of  apical  alveolar  walls,  and 
next  gradual  loss  of  root-substance, 
in  exact  correspondence  with  the 
growth  of  the  permanent  teeth. 
The  lines  in  the  illustration  (Fig. 
140)  show  the  extent  of  root-loss 
of  each  tooth  at  successive  periods. 
To  comprehend  the  nature  of 
the  processes  involved  it  is  essential 
to  obtain  an  accurate  view  of  the 
anatomical  conditions  existing  prior 
to  and  during  the  loss  of  the  de- 
ciduous teeth  and  the  appearance 
of  those  of  the  permanent  denture. 
The  teeth,  both  temporary  and  the 
partially  formed  crowns  of  the  per- 
manent teeth,  lie  in  that  portion  of 
the  bone  called  the  alveolar ;  that 
is,  the  portion  of  the  lower  jaw 
above  the  inferior  dental  canal,  and 
in  the  upper  jaw  below  the  infra-orbital  foramen.  The  cuspid  crowns  in 
both  jaws  are  more  deeply  seated  than  are  any  of  the  other  teeth, 
and  in  the  lower  jaw  are   deeper  than  the  mental  foramen.     Before 


SECOND  DENTITION. 


197 


resorption  of  the  roots  of  the  deciduous  teeth  begins  the  temporary 
teeth  occupy  a  segment  of  alveolar  bone  of  nearly  as  great  a  radius  as 
that  required  for  the  permanent  teeth,  but  the  depth  of  which,  from 
infra-orbital  or  mental  foramen  to  the  alveolar  margins,  is  decidedly 
less  than  that  of  the  adult  jaw.  In  the  base  of  this  segment,  separated 
from  the  bodies  of  the  bones  by  bony  lamina  and  from  the  pericemen- 

FiG.  140. 


Decalcification  of  the  deciduous  teeth.    The  numbers  indicate  years.    (Peirce.) 

tum  of  the  temporary  teeth  by  a  layer  of  bone,  lie  the  developing 
permanent  teeth,  with  the  exception  of  the  molars,  which  lie  in  the 
posterior  portion  of  the  alveolar  bone,  which  at  the  period  under  con- 
sideration (about  five  years)  is  of  slight  extent  compared  with  its  adult 
size,  both  as  regards  depth  and  length.  Its  length,  from  the  distal  wall 
of  the  temporary  second  molar  to  the  base  of  the  coronoid  process,  is 
but  little  more  than  sufficient  to  easily  accommodate  the  crown  of  the 
permanent  first  molar ;  its  depth  between  gum-surface  and  the  roof  of 
the  inferior  dental  canal  is  but  little  more  than  sufficient  to  accommo- 
date the  height  of  the  crown. 

The  buccal  cusps  of  the  crowns  of  the  developing  bicuspids  lie  in 
the  triangular  pyramidal  depressions  between  the  roots  of  the  temporary 
molars,  separated  from  the  roots,  as  are  all  of  the  other  crowns  from  the 
roots  of  their  deciduous  predecessors,  by  laminae  of  bone  and  perice- 
mentum. The  crowns  of  cuspids  and  incisors  lie  inward  lingually  of 
the  roots  of  the  deciduous  teeth. 


ERUPTION    OF    PERMANENT    FIRST    MOLAR. 

This  tooth,  vulgarly  called,  from  the  time  of  its  eruption,  the  sixth- 
year  molar,  has  a  process  of  eruption  similar  to  that  of  the  deciduous 
teeth.  Being  the  largest  tooth  of  the  dental  series,  the  passage  of  its 
large  crown  requires  the  resorption  of  an  extensive  amount  of  gum 
and  alveolar  tissue ;  this  process  is  usually  accomplished  in  the  course 
of  a  few  months.  It  diifers  in  no  respect  from  the  physiological  erup- 
tion of  the  temporary  tooth.  It  is  to  be  recalled  that  in  the  develop- 
ment of  the  jaws  two  divisions  of  the  bone  are  recognized,  the  alveolar 


198 


DENTITION. 


portion  and  body  portion ;  normally  their  development  proceeds  together 
and  harmoniously.  With  the  growth  of  the  alveolar  process  which 
forms  about  the  roots  of  the  permanent  first  molars  the  distances  from 
the  alveolar  border  to  the  levels  of  infra-orbital  and  mental  foramina 
increase — i.  e.,  the  alveolar  bone  is  growing  in  height  throughout  its 
length.  This  growth  normally  causes  a  separation  of  the  anterior  teeth, 
which  is  to  be  regarded  as  the  precursor  to  resorption  of  the  roots  of 
these  teeth. 

EESOEPTION. 

In  advance  of  the  crown  of  the  tooth  in  process  of  eruption  a  num- 
ber of  large  multinucleated  cells  make  their  appearance,  whose  office  it 
is  to  ejffect  the  removal  of  tissue  interfering  with  eruption.  The  origin 
of  these  cells  is  not  known  ;  by  some  they  are  believed  to  be  transformed 
osteoblasts,  by  others,  leucocytes.  The  latter  is  the  more  probable  expla- 
nation ;  that  is,  these  cells  are  phagocytes,  named  from  their  partic- 
ular function  osteoclasts,  or  bone-destroyers  ;  those  attacking  and  re- 
moving the  roots  of  teeth  are  called  odontoclasts.  In  the  light  of  present 
physiological  theories  it  is  believed  that  these  cells  have  a  secretion  cap- 
FiG.  141.  al^le  of  digesting    bony  tissue  and  dentin ; 

that  is,  they  remove  molecularly  the  tissues 
interfering  with  eruption.  It  is  possible  that 
they  secrete  a  ferment  or  solvent  which  effects 
the  solution  of  bone  and  dentin,  the  solution 
being  removed  by  the  lymphatic  system. 
As  the  result  of  the  presence  and  life 
of  these  cells,  first,  disappearance  of  the 
bony  lamina  between  the  crowns  of  the 
permanent  and  the  roots  of  the  deciduous 
teeth  occurs ;  next,  the  roots  of  the  latter 
are  attacked  when  the  permanent  crown 
impinges  upon  the  deciduous  root.  It  is 
possible  that  this  element  of  pressure,  of  ad- 
vance of  the  permanent  crown,  may  be  the 
cause  of  the  presence  of  these  multinu- 
cleated cells  (see  Chapter  I.,  Reproduction 
of  Cells).  These  cells  lie  between  crown  and 
root,  and  as  the  latter  is  removed  the  former 
advances.  It  will  be  observed  from  the  re- 
lationship of  parts  that  resorption  does  not 
begin  at  the  very  apex  of  the  root.  Those  portions  of  the  alveolar 
process  which  immediately  surround  the  roots  of  the  temporary  teeth 
also  undergo  resorption,  a  new  process  being  built  about  the  roots  of 
the  permanent  teeth  (Fig.  141). 


Showing  the  relations  of  an  erup- 
ting permanent  tooth  to  its  decid- 
uous predecessor :  A,  A,  A,  odonto- 
clasts. 


SECOND  DENTITION.  199 

The  process  of  eruption  of  the  permanent  second  nioUirs  is  the 
same  as  that  of  the  first  mohirs.  The  development  of  the  jaws 
increasing  the  distance  between  the  distal  wall  of  the  first  molar  and 
the  base  of  the  coronoid  process,  proceeds  until  there  is  space  enough 
between  the  second  molar  and  the  coronoid  process  to  admit  the  crown 
of  the  third  molar,  which  erupts  late,  by  a  process  similar  to  that  of  the 
other  permanent  molars.  Not  until  this  eruption  is  complete  do  the 
maxillffi  acquire  their  full  adult  forms. 

DISORDERS   OF   THE  SECOND    DENTITION. 

Provided  that  nothing  occurs  during  the  period  of  second  dentition 
to  interfere  with  the  normal  resorption  of  the  roots  of  the  temporary 
teeth,  the  process  of  dentition  as  regards  the  twenty-eight  anterior  teeth 
proceeds  in  an  orderly  manner.  Given  such  interference,  abnormalities 
of  the  second  dentition  make  their  appearance  ;  many  of  these  will  be 
discussed  in  the  succeeding  chapter,  under  the  head  of  malpositions. 
It  will  be  recalled  that  the  teeth  are  an  evolution  of  the  dermoid  sys- 
tem, which  fact  possesses  pathological  significance  in  certain  acute  and 
specific  skin  diseases.  It  is  noted  in  some  cases  of  the  eruptive  fevers 
of  children,  particularly  when  the  child  is  much  debilitated,  that  after 
the  cessation  of  the  acute  disease  a  necrotic  affection  of  the  jaw  occurs, 
involving^  the  alveolar  bone  and  its  contents.  As  manv  of  these  cases 
occur  between  the  ages  of  three  and  seven  years,  the  temporary  teeth 
are  still  In  situ  ;  these  with  the  partially  developed  permanent  teeth  and 
the  enclosing  bone  may  be  exfoliated.  The  necrotic  process  may  involve 
but  one  tooth,  or  may  include  all  of  the  temporary  teeth,  their  successors 
and  a  larw  mass  of  bone.^  The  disease  with  Avhich  this  necrosis  is  most 
frequently  associated  is  scarlet  fever  f  it  is  also  found  as  a  sequel  of 
measles  and  smallpox.  It  will  be  observed  that  all  of  these  diseases 
are  forms  of  specific  dermatitis,  and  the  teeth  as  part  of  the  dermoid 
system  are  affected  (see  Chapter  XL).  "  The  cases  prior  to  exfoliation 
of  the  bone  exhibit  a  stripping  of  the  periosteum,  apjjarently  beginning 
about  the  necks  of  the  teeth.  A  discharge  of  pus  having  a  fetid  odor 
is  present,  and  the  soft  tissues  may  be  raised  from  the  bone  for  a  vari- 
able extent ; "  that  is,  there  is  evidence  of  purulent  periostitis.  In  the 
course  of  some  weeks,  six  or  eight,  the  necrotic  bone  and  its  contents 
exfoliate.  Salter  observes  that  the  sequestra  forming  after  severe  scar- 
let fever  are  much  more  extensive  than  those  which  form  as  a  sequel  of 
measles. 

Treatment. — In  the  absence  of  any  guide  as  to  the  amount  of  bone 
which  has  died,  the  operator  is  compelled,  as  in  all  cases  of  necrosis,  to 
adopt  palliative  measures,  the  most  important  one  being  the  free  and 

^  Salter,  Dental  Pathology.  *  Ihid. 


200  DENTITION. 

frequent  use  of  antiseptic  washes  and  sprays — hydrogen  dioxid.  The 
prescription  of  Garretson  for  such  cases  should  be  applied  to  hasten 
exfoliation  and  to  stimulate  still  vital  parts — /.  e.,  enough  tincture  of 
capsicum  and  myrrh  (tr.  capsici  et  myrrhse)  is  to  be  added  to  a  glass 
of  water  to  cloud  the  water ;  this  is  then  to  be  used  freely  as  a  stimu- 
lant and  astringent  mouth-wash.  As  soon  as  the  sequestrum  is  loose 
it  should  be  removed ;  the  parts  heal  by  granulation,  provided  due 
attention  be  paid  to  the  general  physical  welfare  of  the  child. 

Non-resorption  of  Temporary  Roots. — The  failure  of  resorption 
of  the  roots  of  temporary  teeth  will  necessarily  interfere  with  the  erup- 
tion of  the  permanent  teeth.  Perhaps  the  most  common  cause  of  failure 
of  root-resorption  of  the  temporary  teeth  is  to  be  found  in  septic  con- 
ditions of  their  roots.  Whether  the  pulp  of  a  tooth  performs  any 
active  office  in  the  process  of  root-resorption  is  not  known ;  the 
evidence  that  it  does  is  but  imperfect  and  indirect,  so  that  for  the 
reasons  of  failure  of  resorption  search  must  be  made  outside  of 
the  pulp-chamber.  The  pulp  of  a  temporary  tooth  dead  as  the  re- 
sult of  invasion  of  caries  undergoes  decomposition  ;  infection  of  the 
pericementum  occurs,  and  septic  pericementitis  results.  An  abnormal 
condition  is  established,  and  resorption  does  not  occur ;  the  conditions 
are  not  favorable  for  the  presence  and  activity  of  odontoclasts  ;  should 
they  be  present,  their  vital  activities  are  poisoned  by  the  j)roducts  of 
the  micro-organisms  present — instead  of  functionating  they  die.  An 
irregular  resorption  does,  however,  occur  over  some  portions  of  the 
roots.  If  the  purulent  condition  be  removed  and  the  parts  be  made  asep- 
tic, resorption  occurs  but  is  delayed.  It  is  evident  that  the  underlying 
permanent  tooth  is  imprisoned  until,  by  a  loss  of  overlying  structures, 
it  is  free  to  move  into  position.  Many  of  these  dead  teeth  and  dead 
roots  are  removed  by  a  process  similar  to  that  which  occurs  in  the  cast- 
ing off  of  the  useless  roots  of  the  permanent  teeth ;  a  general  resorp- 
tion of  the  provisional  alveolar  bone  occurs,  and  the  root  is  cast  out ;  its 
separation  from  the  soft  tissues  may  again  be  accomplished  by  the  pro- 
cess of  suppuration. 

Treatment. — If  a  pulpless  deciduous  tooth  be  present  in  the 
dental  arch  when  the  corresponding  permanent  tooth  of  the  opposite 
side  of  the  jaw  is  in  process  of  eruption,  the  pulpless  tooth  should  be 
extracted.  Prior  to  this  time  the  deciduous  tooth  should  be  retained, 
provided,  by  appropriate  antiseptic  treatment,  its  pericementum  can  be 
brought  to  and  be  maintained  in  a  healthy  condition.  The  space 
between  adjoining  teeth  occupied  by  the  temporary  teeth  affords  room 
for  the  accommodation  of  the  permanent  successors.  Too  early  extrac- 
tion is  followed  by  insufficient  space.  This  is  particularly  notable  fol- 
lowing premature  loss  of  the  deciduous  second  molars. 


SECOND  DENTITION.  201 

Eruption  of  Molars. — It  is  rare  that  abnormalties  are  associated 
with  the  progress  of  the  eruption  of  the  first  or  second  permanent 
molars.  It  may  be  noted  in  very  rare  cases  that  there  is  a  failure  of 
harmony  in  the  development  of  alveolar  and  body  bone  ;  that  insuf- 
ficient space  exists  posteriorly  for  the  accommodation  of  the  second 
molars.  They  suffer  more  or  less  impaction,  particularly  in  the  lower 
jaw  ;  as  a  rule,  subsequent  development  of  the  body  of  the  bone  affords 
the  needed  space.  It  is  with  the  eruption  of  the  third  molars  that 
aberrations  are  most  frequently  noted. 

Pathological  Eruption  of  the  Third  Molars. — At  the  time 
of  eruption  of  the  permanent  second  molars,  the  third  molars  in  both 
jaws  occupy  recesses  in  the  alveolar  bone  and  are  in  but  a  partial  state 
of  development.  In  the  upper  jaw  these  recesses  occupy  the  tuberosity 
of  bone  bounded  anteriorly  by  the  distal  Av^alls  of  the  second  molars,  and 
posteriorly  by  the  tips  of  the  pterygoid  processes  of  the  sphenoid  bone. 
This  rounded  prominence  grows  larger  as  the  development  of  the  teeth 
proceeds.  It  is  unusual  that  much  lack  of  space  exists  for  the  accommo- 
dation of  the  tooth.  Should  the  development  of  the  tuberosity  not  keep 
pace  with  that  of  the  tooth,  and  eruption  proceed,  the  direction  of  erup- 
tion is  outward  toward  the  cheek  ;  the  relations  of  the  pterygoid  pro- 
cess and  of  the  palate  bone  with  the  tuber- 

^  ,  .  Fig.  142. 

osity  make  a  path  of  greatly  increased  resist- 
ance at  the  palato-alveolar  angle  ;  backward 
eruption  is  prevented  by  the  pterygoid 
processes ;  direct  eruption,  by  the  second 
molar  and  pterygoid  process,  so  that  the 
path  of  least  resistance  is  outward  toward 
the   cheek.     It   is    occasionally   noted  that 

this    tooth      erupts     with      its     occlusal     face    Abnormal    eruption   of  the   upper 

pointed  directly  toward  the  cheek,  a  posi- 
tion at  right  angles  to  that  it  occupies  normally  (Fig.  142).     In  rare 
instances  the  upper  third  molar  is  caught  between  the  second  molar 
and    the    pterygoid    process ;    in   such  cases   eruption   is   prevented  or 
delayed  (.see  Chapter  X.). 

In  cases  of  difficult  eruption  conditions  may  arise  which  tend  to 
increase  the  morbid  processes  and  to  alter  their  character.  There  is, 
first,  an  irritative  hyperemia  of  the  soft  tissues  surrounding  the  erupt- 
ing tooth.  As  this  is  the  region  of  the  mouth  least  affected  by  dental 
cleansing  agents  used  by  the  patient,  and  in  which  the  irrigating  office 
of  the  saliva  is  very  incomplete,  fermentation-processes  are  common ; 
their  products  added  to  a  part  in  active  hyperemia  can  but  aggravate 
the  condition.  Pyogenic  cocci,  usual  inhabitants  of  the  mouth,  may 
infect  the  tissues,   finding  with  numerous  other  organisms  a  habitat 


202  DENTITION. 

between  the  tooth  and  the  swollen  gum-margin ;  thus  it  is  that  pus- 
formation  may  accompany  the  delayed  eruption.  If  the  swollen  parts 
be  incised,  and  antiseptic  sprays  be  directed  into  all  of  the  recesses, 
a  disappearance  of  symptoms  is  noted. 

It  is  in  connection  with  the  lower  third  molar  more  frequently  than 
with  any  of  the  permanent  teeth  that  pathological  eruption  is  most  com- 
mon. In  civilized  races  the  room  for  the  accommodation  of  the  crown 
of  the  lower  third  molar,  between  the  distal  wall  of  the  second  molar 
and  the  base  of  the  inner  root  of  the  condyloid  process,  is  frequently 
but  scant ;  the  tendency  of  maxillary  development  is  to  render  restricted 
space  the  rule  rather  than  an  exceptional  occurrence.  The  crown  of 
the  tooth  does  not  make  its  appearance  until  developmental  changes 
have  secured  sufficient  space  for  it.  This  may  delay  its  eruption  for 
months  or  years,  and  in  some  cases  prevent  eruption  altogether.  In 
others  the  development  of  the  tooth  may  proceed  after  all  develop- 
mental changes  in  the  jaw  have  ceased,  and  the  teeth  are  entirely  encap- 
suled  (see  Chapter  X.,  Impacted  Teeth).  The  delay  in  eruption  in 
the  more  severe  cases  is  due  to  improper  configuration  of  the  bony  sur- 
roundings ;  the  delay  in  milder  cases  may  be  due  to  imprisonment  by 
soft  tissues ;  in  other  cases  pathological  conditions  are  caused  not  so 
much  by  imprisonment  as  by  irritation  of  the  soft  tissues. 

It  is  almost  the  rule  that  eruption  of  the  lower  third  molars  is 
attended  by  some  degree  of  discomfort.  Usually  for  some  months 
before  the  cusps  of  the  crown  make  their  appearance  through  the  gum. 
there  is  an  ill-defined  uneasiness  about  the  jaws  and  some  stiiFness  of 
the  muscles  of  mastication.  These  symptoms  disappear  and  recur  at 
irregular  intervals  until  the  crown  is  entirely  through  the  gum.  Inter- 
ference is  rarely  called  for;  the  usual  antiseptic  mouth-washes  employed 
by  the  patient  guard  against  infection  of  the  irritated  parts.  In 
cases  where  the  gum  presents  a  swollen  and  irritated  appearance  relief 
follows  the  application  to  the  affected  gum  of  iodin  tincture.  Should 
the  mesial  half  of  the  crown  be  free  and  the  posterior  half  covered  by  a 
curtain  of  gum,  it  is  advisable  that  the  pocket  between  the  tooth  and 
gum  be  eradicated,  as  it  forms  a  recess  in  which  the  active  causes  of 
dental  caries  thrive,  and  in  which  fermentations  arise,  forming  irritating 
products.  In  the  more  severe  cases  these  may  induce  active  inflamma- 
tion of  the  soft  tissues  to  an  alarming  extent.  In  all  of  these  cases 
where  bands  or  curtains  of  gum-tissue  are  the  cause  retarding  erup- 
tion the  indication  is  to  freely  divide  the  tissue  longitudinally.  The 
precaution  should  be  taken  to  spray  the  parts  freely  with  an  antiseptic 
before  and  after  making  the  incision.  The  cutting  may  be  rendered 
painless  by  slipping  under  the  gum-flap  for  a  few  moments  a  pledget 
of  cotton  containing  a  6  per  cent,  solution  of  cocain  hydrochlorid,  the 


SECOXD  DENTITION.  203 

same  solution  being  painted  over  the  flap.  The  incision  is  made  with  a 
pointed  bistoury,  its  point  being  directed  toward  the  crown. 

It  is  when  some  portion  of  the  posterior  segment  of  the  crown  is 
held  back  by  bony  tissue  that  the  more  severe  symptoms  appear,  usually 
in  the  degree  of  bony  imprisonment.  The  general  character  of  the 
pains  in  these  cases  is  heavy  and  rheumatic,  indefinitely  located  about 
the  angle  of  the  jaw  and  the  ear.  Combined  with  pain  is  usually 
marked  stiffness  of  the  masseter  muscle  ;  in  the  more  severe  cases  the 
spasmodic  contraction  of  the  muscle  may  simulate  trismus  of  that  side. 
These  symptoms  may  appear  irrespective  of  any  marked  evidences  of 
inflammatory  reaction  of  the  tissues  around  the  imprisoned  crown.  The 
pains  are  of  the  type  called  periosteal — dull,  gnawing,  heavy. 

The  pockets  between  gum  and  tooth-crown  offer  passageways  for 
infection  of  deeper  tissues,  so  that  it  is  not  surprising,  particularly  in 
unclean  mouths,  that  inflanmiation  and  suppuration  of  the  tissues  about 
the  part  may  occur.  The  inflammatory  process  may  extend  to  the  neigh- 
boring soft  tissues ;  there  is  usually  increased  rigidity  of  the  masseter 
muscle,  so  that  it  is  wdth  the  utmost  difficulty  that  the  mouth  can  be 
opened  even  wnth  mechanical  assistance.  It  is  not  unusual,  therefore, 
as  a  result  of  inability  to  reach  the  parts  for  local  therapeutics,  for 
suppuration  to  extend  far  beyond  the  original  focus  of  irritation. 
Relief  is  not  attainable  until  free  vent  for  the  pus  is  given,  the  dis- 
charge being  often  through  the  cheek. 

Treatment. — Nowhere  more  than  here  does  the  dictum  of  surgery 
— remove  the  source  of  irritation,  apply.  The  source  of  irritation 
common  to  all  of  the  cases  being  the  tooth  for  which  there  is  insuf- 
ficient room,  the  general  indication  is  its  extraction.  This  operation 
is,  however,  frequently  attended  with  difficulties  which  render  it  in 
some  cases  highly  impracticable.  In  the  least  severe  cases  of  bony 
imprisonment,  if  untoward  symptoms  can  be  held  in  abeyance  for  some 
months,  the  obstruction  to  the  tooth's  advance  may  be  removed  and 
eruption  be  completed.  The  principal  object  during  the  period  of  delay 
is  to  prevent  infection  of  the  parts,  so  that  antiseptic  mouth-washes  play 
an  important  part  in  the  treatment.  Local  irritation  may  he  largely 
allayed  by  the  free  application  of  tincture  of  iodin  diluted  with  alcohol. 

If  the  rheumatic  pains  about  the  jaw  and  neck  and  the  stiffness 
of  the  masseter  muscle  be  of  moderate  degree,  relief  is  afforded  by 
free  massage  of  the  parts.  If  the  pains  assume  a  neuralgic  character, 
much  relief  may  be  secured  through  the  use  of  sedative  ointments,  such 
as  those  of  aconitia  and  veratria. 

I^.  Aconitia,  gr.  j  ; 

Cerat.  simp.,  3j. — M.     (Flagg.) 


204  DENTITION. 

In  making  this  ointment  it  is  to  be  manipulated  so  that  it  is 
certain  the  drug  is  evenly  distributed  throughout  the  cerate.  A 
minute  portion  of  the  ointment  is  rubbed  over  the  masseter  mus- 
cle in  front  of  the  ear  and  about  the  angle  of  the  jaw  by  means  of 
the  finger. 

Flagg  commends  the  efficacy  of  an  ointment  of  veratria  when  that 
of  aconitia  fails  to  procure  relief: 

^.  Veratria,  gr.  xx  ; 

Cerat.  simp.,  3J. — M.     (Flagg.) 

S.  Used  in  the  same  manner. 

It  should  be  noted  that  both  of  these  ointments  are  actively  poison- 
ous, and  should  be  kept  from  absorbent  surfaces. 

Should  severe  symptoms  arise,  extraction  is  imperatively  demanded, 
and  had  best  be  done  before  increasing  stiffness  of  the  muscles  inter- 
feres with  the  proper  opening  of  the  mouth.  In  some  cases  there  is 
no  doubt  of  the  practicability  of  extracting  the  third  molar ;  when  the 
crown  is  freely  exposed  and  not  decidedly  imprisoned  by  the  coro- 
noid  process,  forceps  may  grasp  it  firmly  and  by  an  inward  and  upward 
rotary  movement  the  tooth  is  extracted.  In  cases  of  more  decided  im- 
paction, the  resistance  offered  outwardly  by  the  external  root  of  the 
coronoid  process,  backward  by  the  internal  root  of  the  same,  and  for- 
ward by  the  second  molar,  may  render  extraction  impossible  without 
the  previous  removal  of  some  portion  of  the  bone.  It  is  evident  that 
in  such  a  case  attempts  at  forcible  extraction  would  be  inevitably  fol- 
lowed by  fracture  of  bone  or  of  the  tooth,  the  latter  occurring  more 
frequently  than  the  former.  It  is  advisable — indeed,  almost  neces- 
sary— in  such  cases  that  the  second  molar  be  the  tooth  extracted.  This 
applies  also  to  the  cases  of  more  decided  imprisonment  with  active 
inflammation. 

Where  stiffness  of  the  masseter  muscle  fixes  the  jaws  so  that  they 
cannot  be  separated  sufficiently  to  secure  a  grasp  upon  either  the  third 
or  even  the  second  molar,  mechanical  violence  may  be  necessary  to  sepa- 
rate them.  A  jaw-separator  is  placed  in  position,  the  patient  etherized, 
and  the  separator  operated  until  sufficient  space  is  gained  to  secure  a 
grasp  upon  the  tooth ;  failing  the  third  molar,  grasping  the  second  molar. 
The  muscle  is  sometimes  of  board-like  hardness,  and  resists  the  force 
of  the  separator.  Indeed,  such  resistance  may  be  offered  that  separa- 
tion can  only  be  effected  by  fracture  of  the  muscle  or  of  the  bone.  In 
these  cases  an  antiseptic  spray — hydrogen  dioxid — is  directed  against 
and  about  the  third  molar  for  a  period  of  ten  minutes  or  longer ;  as 
soon  as  sterilization  is  assured  a  curved  bistoury  is  used  to  divide  the 


SECOND  DENTITION.  205 

swollen  gum-tissue  about  the  tooth,  and  cold  compresses  arc  placed  over 
the  angle  of  the  jaw.  The  antiseptic  spray  is  subsequently  applied  at 
intervals  of  about  two  hours.  If  local  massage  be  practised  in  addition, 
the  swelling  and  muscular  hardness  usually  disappear  in  a  few  days, 
when  the  jaws  may  be  separated  sufficiently  to  allow  extraction  of  the 
molar  (see  Impaction  of  Teeth,  Chapter  X.). 


CHAPTER   X. 

MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

In  the  majority  of  persons  the  entire  denture  consists  of  thirty- 
two  teeth  arranged  in  two  parabolic  curves,  one  upper  and  one  lower, 
each  semi-denture  having  sixteen  teeth.  jSTormally  both  the  upper  and 
the  lower  teeth  are  bilaterally  symmetrical,  the  eight  teeth  of  either 
half  of  the  upper  or  lower  denture  corresponding  exactly  in  size,  form, 
and  position  with  the  corresponding  eight  teeth  of  the  opposite  side. 
Each  tooth  of  each  upper  and  lower  eight,  while  differing  in  size  and 
details  of  form  from  all  of  its  fellows,  yet  bears  a  definite  relationship 
to  each  of  the  others  as  regards  size. 

Abnormalities  of  the  teeth  are  found  associated  with  position,  size, 
form,  and  structure.  Aberrations  in  form,  structure,  and  size  are  in- 
cluded under  the  head  of  malformations  of  the  teeth  ;  aberrations  of 
position  are  discussed  under  the  head  of  malpositions  of  the  teeth. 
The  particular  section  of  dentistry  relating  to  malpositions  of  the  teeth 
is  by  general  consent  made  a  special  department  of  operative  dentistry, 
that  of  orthodontia ;  but  many  of  the  phases  of  the  subject  are  of  great 
pathological  interest,  although  the  therapeutic  measures  usually  de- 
manded are  mechanical  in  character  and  clearly  belong  to  the  fields  of 
operative  and  prosthetic  dentistry. 

Malformations  of  the  Teeth. 

Malformations  of  the  teeth  may  be  either  macroscopic  or  micro- 
scopic ;  they  may  be  evident  to  the  unaided  eye,  or  may  require  for 
their  detection  special  preparation  for  observation  under  the  microscope. 

MICROSCOPIC    malformations. 

Microscopic  or  histological  defects  of  the  teeth  may  affect  any  of  the 
dental  tissues,  enamel,  dentin,  cementum,  pulp,  or  pericementum. 

Enamel. — Defects  in  enamel-structure  range  from  any  degree  of 
orderliness  in  the  even  distribution  of  globular  bodies  and  cementing- 
substance  in  the  tissue  to  gross  aberrations  in  formation.  The  finer 
variations  of  structure  are  not  easily  recognizable. 

Theoretically  perfect  enamel  should  show  in  longitudinal  section  a 
series  of  squares  of  uniform  size  built  into  rods,  the  spaces  between  the 
squares  and  rods  being  marked  by  lines  of  cementing-substance  having 

206 


MALFORMATIONS   OF  THE  TEETH. 


207 


a  refractive  index  slightly  different  from  that  of  the  squares.  While 
.such  a  structure  is  perhaps  never  found,  it  is  difficult  to  draw  a  line 
where  aberrations  from  such  a  standard  become  pathological.  An  arbi- 
trary standard  might  be  assumed  as  follows :  regard  any  enamel  as 
pathological  where  areas  of  it  differ  from  its  general  substance  to  such 
an  extent  as  to  have  a  decidedly  different  refractive  index.  A  typical 
form  of  abnormality  is  noted  in  what  are  known  as  white  spots  of  the 
enamel,  areas  in  which  an  opaque  surface  exists  instead  of  the  normally 
translucent  enamel. 

In  Fig.  143  is  represented  a  magnification  of  500  diameters  of  a 
section    made  of  a  portion  of  a  white  spot  where  it  adjoins   normal 


Fig.  143. 


/ 


Margin  of  sectiuii  through  "  white  spot.' 


(Williams.) 


enamel.  The  area  of  white  spot  when  viewed  by  transmitted  light 
shows  dark  in  the  section.  The  enamel  of  the  white  spot  is  more  or 
less  granular  in  structure,  and  its  globules  are  not  fused  together  in  rods 
as  in  normal  enamel.  Williams  suggests  as  an  explanation  of  this  con- 
dition that  there  is  a  deficiency  of  the  cementing-substance. 


208       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

Fig.  144. 


Antero-posterior  section  of  human  lower  molar,  showing  defects  of  structure  in  the  vicinity 

of  sulci.    X  12.     (Williams.) 

Fi».  145. 


Section  of  human  molar,  showing  dentinal  fibrillge  penetrating  enamel.    X  600.    (AVilliams.) 


MALFORMATIONS  OF  THE   TEETH. 


209 


Euamel-forraation  about  the  sulci  of  teeth  is  frequently  faulty ; 
owing  to  an  imperfect  union  of  the  enamel-segments  forming  the  cusps 
of  the  teeth  minute  fissures  exist  in  the  enamel  ;  these  are  most  marked 
in  the  fissures  of  molars,  as  shown  in  Fig.  144.  The  enamel  bounding 
these  fissures  has  an  irregular  structure. 

The  dentinal  fibrillse  may  penetrate  the  substance  of  the  enamel 
(Fig.  145),  occupying  defined  channels  in  its  substance;  this  is  a 
developmental  accident.  AVilliams  points  out  that  the  organic  filaments 
from  the  dentin  become  atrophied  with  the  progress  of  enamel-formation 
and  canals  remain.  The  probable  explanation  of  this  condition  is  that 
a  process  of  an  odontoblast  prior  to  enamel-deposition  finds  its  way 
through  the  soft  pre-enamel-deposit,  and  enamel-deposit  encloses  it, 
calcification  occurs,  and  a  permanent  defect  results.  This  condition,  as 
also  many  other  variations  of  structure  found  in  the  dental  tissues  of 
man,  are  shown  by  Williams  to  have  their  normal  prototypes  in  the 

Fig.  146. 


Section  of  human  bicuspid,  showing  mass  of  very  imperfectly  calcified  enamel  projected  into  the 
dentin,  with  coarse  fissures  leading  to  the  surface.    X  "5.    (Williams.) 


dental  tissues  of  lower  animals ;  for  example,  the  penetration  of  den- 
tinal fibrillfe  into  enamel  is  a  normal  condition  in  the  teeth  of  the  kan- 
garoo. The  presence  of  organic  tissue  in  the  enamel  of  man  is,  how- 
ever, always  to  be  regarded  as  pathological.  Such  conditions  are  not 
to  be  confounded  with  fissures  of  enamel  where  large  lines  of  faulty 
calcification  or  non-calcification  extend  through  the  thickness  of  enamel 
(Fig.  146). 

14 


210       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

Enamel,  even  normal  enamel,  is  not  of  uniform  composition  ;  were 
it  so,  it  would  exhibit,  in  addition  to  an  orderly  arrangement  of  its  his- 
tological elements,  a  uniformity  in  color.  So  common  are  differences  in 
this  direction  that  the  presence  of  pigment-bands  must  be  regarded  as 
normal.  It  is  the  rule  to  find  enamel  traversed  by  deeply  pigmented 
parallel  bands  (Fig.  147)  which  pass  obliquely  upward  from  the  surface 

Fig.  147. 


Section  of  human  incisor,  showing  "bands  of  Retzius  "  and  marked  stratification  of 
enamel.    X 125.    (Williams.) 

of  the  dentin  to  the  surface  of  the  enamel.  These  are  termed  the 
bands  of  Retzius  (see  Chapter  VII.) ;  they  appear  to  mark  the  size 
of  the  enamel-cap  at  successive  periods  of  its  growth. 

Stratification  and  striatiou  of  the  enamel,  as  shown  by  Williams,  must 
be  regarded  as  normal  physiological  records  of  the  mode  of  enamel- 
formation. 

All  of  these  histological  defects  represent  variations  of  deposition,  of 
formation,  no  doubt  due  to  fluctuations  of  the  nutritive  processes  of  the 
child  at  the  time  of  tooth-formation.  Histological  records  made  in 
the  enamel  are  not  like  those  made  in  other  tissues,  for  there  is  no 
nutritive  provision  through  wdiich  such  defects  can  be  remedied  at 
subsequent  periods. 

Profound  nutritive  disturbances,  such  as  those  attending  hereditary 
syphilis  in  children,  affect  the  structures  of  the  teeth.     One  of  the  gross 


MALFORMATIONS  OF  THE  TEETH. 


211 


results  of  this  disease  is  a  common  malformation  of  the  general  form  of 
the  incisors.  The  hard  tissues  of  such  teeth  exhibit  microscopic  evi- 
dences of  faulty  histology  ;  they  are  dull  and  opaque  and  traversed  by 
irregular  bands.  Viewed  in  section  the  enamel  of  such  teeth  is  seen  to 
be  almost  structureless  (Fig.   148).    Williams  found  that  the  contents 


Fig.  148. 


Fig.  149. 


Section  of  enamel  from  syphilitic  tooth,  with  appearances  resembling  the  lacunae  of  cementum. 

X600.     (Williams.) 

of  the  large  irregular  spaces  in  this  enamel  did  not  respond  to  stains — 
i.  e.,  did  not  contain  organic  matter. 

There  is  evidence  that  other  forms  of  specific  dermatitis — scarlet 
fever  and  measles — which  occur  at  an  early  age  may  affect  the  forma- 
tion of  enamel.  The  defects  attrib- 
uted to  the  exanthemata  are  irregular 
pits  upon  the  crowns  of,  particularly, 
the  incisors  (Fig.  149).  With  a  history 
of  a  case,  including  the  age  of  the  child 
at  the  period  of  the  disease,  if  exam- 
ination be  made  of  the  positions  of 
the  defects,  the  age  will  serve  as  an  in- 
dication as  to  whether  there  has  been  any  connection  between  the  eruptive 
fever  and  the  dental  malformation.  For  example,  if  enamel -pits  upon 
incisors  have  been  caused  by  an  eruptive  fever  between  the  ages  of  four 
and  five,  they  should  occupy  about  the  half-way  area  of  the  crown-face  ; 
it  is  evident  that  the  enamel  being  already  formed  about  the  cutting-edge 


Teeth  of  eruptive  fevers. 


212       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 


Fig.  150. 


of  the  tooth,  alterations  of  nutrition  could  not  affect  the  already  formed 
tissue.  In  cases  where  a  causal  association  of  enamel-defects  with  the 
eruptive  fever  is  made  out  with  reasonable  clearness  it  is  usual  to 
find  all  of  the  crowns  of  the  teeth  which  are  in  process  of  formation 
affected  in  a  similar  manner.  The  defects  and  pittings  are  so  pronounced 
in  some  of  these  cases  as  to  give  a  general  honeycombed  appearance  to 
the  crowns  ;  such  teeth  are  known  in  dental  parlance  as  "  honeycombed 
teeth." 

Cases  are  observed  where  there  has  been  a  formative  crisis  to  the  ex- 
tent of  having  no  enamel  whatever  formed  over  the  occlusal  section  of 
the  crown,  its  deposit  on  the  remainder  of  the  crown  being 
quite  normal  (Fig.  150). 

D.  B.  Freeman  ^  records  the  case  of  an  individual,  aged 
twenty-six  years,  whose  teeth  anterior  to  the  second  molar 
were  entirely  devoid  of  enamel.  The  condition  was  hered- 
itary, it  appeared  in  both  brothers  and  sisters,  and  could  be 
traced  back  for  three  generations. 

Dentin. — Data  regarding  the  finer  phases  of  defective 
histological  structure  of  the  dentin  are  meagre.  It  has  been  observed 
that  the  dentinal  tubuli  of  some  teeth  are  much  larger  than  in  others 
of  the  same  age,  and,  no  doubt,  future  investigations  with  an  improved 
technique  directed  toward  a  study  of  the  exact  mode  of  den  tin-formation 
will  exhibit  defects  more  certainly. 

The  chief  histological  defects  noted  in  dentin  are  areas  of  faulty  or  non- 
calcification,  called  interglobular  spaces  (see  Chapter  VII.).     These  are 

most  common  in  the  dentin  immedi- 
ately underlying  its  covering  tissue,  so 
common  in  the  dentin  under  the  ce- 
mentum  that  this  portion  of  dentin 
has  been  called  the  stratum  granulo- 
sum,  the  granular  layer  of  Tomes  (Fig. 
151).  In  the  body  of  the  dentin  these 
spaces  have  a  more  irregular  distri- 
bution. 

In  wet  ground-sections  (Rose)  the 
dentinal  filaments  are  seen  to  pursue  an  unbroken  course  through  these 
areas.  The  contents  of  the  interglobular  spaces  react  to  stains  like 
the  sheaths  of  Neumann;  that  is,  they  probably  contain  transitional 
tissue.  These  areas  probably  represent,  as  do  defective  spots  of  enamel, 
periods  of  depressed  vitality  or  of  altered  nutrition.  In  the  light  of 
present  knowledge  regarding  the  subject  they  are  to  be  viewed  as  areas 
in  which  the  calcific  process  was  faulty.  The  malformations  noted  in 
^  See  Guilford,  American  Stjdem  of  JJevtistry^  vol.  iii. 


Fig.  151. 


Dentinal  tubuli  terminating  in  the  spaces  of 
the  granular  layer.    (Tomes.) 


MALFORMATIONS  OF  THE  TEETH. 


213 


connection  with  the  enamel  of  syphilitic  teeth  have  their  analogues  iu 
the  dentin  (Fig.   152). 

Histological  congenital  malformations  of  the  pulp  have  not  been 


Fig.  152. 


Section  showing  interglobular  spaces  iu  dentin  of  a  syphilitic  human  tooth.    (Williams.) 

Fig.  153. 


\  ^    v-.  %\  ■^\\\ 


Section  of  a  bicuspid  with  its  alveolus,  showing  a  pit-like  absorption  upon  the  side  of  the 
root  in  which  the  redeposit  of  the  cementum  has  begun :  o,  dentin ;  b,  cementum ;  c,  peri- 
dental membrane  ;  d,  bone  forming  the  wall  of  the  alveolus  ;  e,  absorbed  area  of  cementum. 
It  will  be  noticed  that  a  new  deposit  of  cementum  has  begun  the  filling  of  the  area,  and  that 
the  soft  tissue  in  the  area  of  absorption  is  of  a  cellular  type.  The  bone  also  shows  the  eftects 
of  absorption  in  the  cutting  away  of  portions  of  the  rings  of  the  Haversian  systems  at  /,  while 
at  g  the  presence  of  osteoclasts  shows  that  absorption  is  in  progress  at  that  point.    (Black.) 

recorded,  the  normal  histology  of  the  organ  not  being  made  out  with 
sufficient  certainty  to  determine  what  appearances  are  to  be  regarded 


214       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

as  abnormal.     Grosser  aberrations,  such  as  those  shown  in  Fig.  103, 
are  made  out. 

Cementum. — As  stated  in  Chapter  VII.,  the  pericementum  con- 
tains numbers  of  multinucleated  cells — odontoclasts  ;  and  their  presence 
is  not  to  be  regarded  as  abnormal.  The  cementum  of  the  roots  of  teeth 
may  exhibit  evidences  of  former  action  of  these  cells  in  excavations  of 
cementum  which  by  a  subsequent  deposition  of  cementum  have  become 
filled.  This  gives  an  irregular  course  to  the  cement-laminse  (Fig.  153). 
These  appearances  are  to  be  regarded  as  not  necessarily  pathological, 
for  the  following  reason  :  for  some  time  (years)  subsequent  to  the  erup- 
tion of  the  teeth  developmental  changes  occur  in  the  alveolar  bones, 
depositions  (subperiosteal)  increasing  their  volume,  are  accompanied  by 
resorption  of  other  portions  of  the  bone,  such  a  balance  being  kept 
between  the  processes  that  the  teeth,  although  shifting  their  positions, 
are  kept  in  normal  occlusion. 

MACROSCOPIC    MALFORMATIONS. 

The  teeth  may  vary  from  normal  either  as  regards  size  or  external 
configuration. 

Variations  as  to  Size. — It  is  patent  to  the  most  casual  observer 
that  the  teeth  vary  as  to  size.  Comparisons  in  this  direction  are  made 
by  an  examination  of  the  upper  central  incisors.  Fig.  154  shows  nearly 
the  extremes  of  observable  sizes  ;  Guilford  ^  points  out  that  excessively 
large  central  incisor-crowns  are  usually  supported  by  abnormally  small 
conical  roots.  Marked  giantism  of  the  central  incisors  usually  occurs 
in  pairs,  the  other  teeth  being  of  normal  size.  On  the  other  hand,  den- 
tal giantism  of  less  degree  may  involve  all  of  the  teeth  of  a  denture. 
The  molar  teeth  are  occasionally  of  enormous  size,  the  bicuspids  rarely 
so,  and  the  cuspids  next  in  frequency  to  the  molars  as  to  the  occurrence 

Fig.  154.  Fig.  155. 


of  giantism.  Guilford  observes  that  giantism  of  the  cuspid-crowns, 
unlike  that  of  the  central  incisors,  is  usually  accompanied  by  a  corre- 
sponding size  of  root.  He  mentions  the  case  of  a  cuspid  measuring 
an  inch  and  a  half  in  length  from  tip  to  tip. 

^  American  System  of  Dentistry,  vol.  iii. 


MALFORMATIONS  OF  THE  TEETH. 


215 


Dwarf  TEETH.-^D(!ficiency  in  size  is  of  more  common  occurrence 
than  excessive  size.  It  appears  to  occur  more  frequently  with  the  upper 
third  molars  and  upper  lateral  incisors  than  with  any  other  teeth.  The 
accompanying  figure  (155)  shows  the  extremes  in  size  between  two  per- 
fectly formed  lower  third  molars.  The  stunting  of  these  and  of  other 
teeth  is,  however,  usually  associated  with  such  an  aberration  of  outward 
form  that  most  dwarf  teeth  must  be  considered  as  abnormal  in  form  as 
well  as  in  size. 

Abnormalities  of  Form. — It  is  in  the  outward  forms  of  teeth  that 
the  greatest  aberrations  are  met  with.  These  range  from  a  slight  exag- 
geration of  one  or  more  of  the  architectural  elements  of  a  tooth  to  such 
malformations  as  produce  an  entire  unlikeness  to  all  tooth-forms — to 
masses  which  cannot  be  properly  classified  as  teeth.  The  most  common 
of  these  malformations  is  an  irregularity  of  cusp-form ;  cusps  are  sup- 
pressed or  are  but  primitive.  A  survey  of  the  primal  basis  of  tooth- 
forms  reveals  that  most  of  these  malformations  are  due  to  improper 
modifications  or  combinations  of  the  formative  cones.  A  common  type 
is  one  or  more  of  the  incisors,  most  frequently  the  lateral  incisors  (Fig. 
156),  presenting  as  unmodified  cones  or  as  conical  masses,  the  normal 
form,  it  will  be  recalled,  being  a  truncated  and  compressed  cone. 

Fig.  156. 


Next  in  point  of  frequency,  the  upper  third  molar  is  seen  to  consist  of 
but  a  single  cone  instead  of  three  fused  cones.  At  the  other  extreme  the 
primitive  cones  may  be  so  combined  as  to  produce  such  irregularities  of 
cusp  and  sulcus  arrangement  that  the  masses  have  lost  all  semblance  to 
normal  tooth-forms. 

Pitted  axd  Grooved  Teeth. — The  effects  of  profound  disturb- 
ance of  the  course  of  nutrition  upon  the  histological  structures  of  the 
teeth  have  been  described.  Such  teeth  are  also  affected  as  to  their  out- 
ward form.  The  malformations  may  consist  of  series  of  irregular 
grooves  and  pittings,  the  crowns  having  the  general  normal  outlines ; 


216       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

or,  again,  the  form  of  the  tooth  itself  may  he  altered  (Fig.  157). 
A  single  groove  across  the  face  of  a  tooth  represents,  no  doubt,  a 
period  of  nutritive  disturbance,  but  cases  are  seen  where  there  is  a 
repetition  of  grooves  separated  by  ridges  of  apparently  normal  enamel, 
indicating  waves  of  nutritional  disturbance,  as  shown  in  Fig.  157,  The 
defective  formation  may  be  confined  to  one  portion  of  the  crowns  of 
the  teeth,  most  commonly  the  occlusal  half  of  the  first  permanent  molars 
and  of  the  incisors. 


Fig.  157. 


Fig.  158. 


Fused  molars. 
Fig.  159. 


Showing  the  front  teeth  grooved  from  the  alterna- 
tion of  perfectly  and  imperfectly  developed 
portions  of  enamel.    (Tomes.) 


Permanent  central  and  lateral  in- 
cisors of  the  upper  jaw,  united 
throughout  the  whole  length  of 
the  teeth.    (Tomes.) 


Fused  Teeth. — It  is  occasionally  observed,  more  frequently  with  the 
upper  second  and  third  molars  than  with  other  teeth,  that,  instead  of  two 
separate  teeth  terminating  the  dental  series,  its  extremity  is  occupied  by 
a  large  dental  mass,  which  upon  examination  shows  the  cusp-elements 
of  both  the  second  and  third  molars  present.  Upon  extraction  this 
mass  is  seen  to  form  but  one  tooth,  but  an  anatomical  analysis  clearly 
reveals  its  dual  character  ;  its  anterior  portion  corresponds  with  a  second 
molar,  its  posterior  with  a  thii'd  molar.  The  root-arrangement  also 
indicates  a  fusion  of  two  teeth  (Fig.  158).  The  anterior  teeth  may  be 
united  after  the  same  manner  (Fig.  159).  It  will  be  observed  that  this 
union  is  most  likely  to  occur  where  the  adjacent  tooth-follicles  have 
least  anatomical  separation  from  their  fellows  ;  it  is  most  common  be- 
tween incisors  and  incisors,  incisors  and  cuspids,  and  second  and  third 
molars.  It  appears  not  to  have  been  observed  in  connection  with  the 
bicuspids,  the  crowns  of  these  teeth  during  the  formative  stage  being 


MALFORMATIONS  OF  THE  TEETH.  217 

confined  between  the  roots  of  the  temporary  molars.  The  follicles  of 
teeth  liable  to  fuse  depend  for  separation  from  one  another  upon  the 
formation  of  bony  walls. 

A  histological  examination  of  these  teeth  exhibits  a  pulp-cham- 
ber, which  may  be  common  throughout,  or,  as  more  frequently  hap- 
pens, distinct  and  separate  root-portions  of  the  pulp  are  observed. 
The  malformations  of  the  crowns  are  clearly  traceable  to  the  fusion  of 
the  lateral  walls  of  the  enamel-organs  before  or  soon  after  enamel- 
formation  begins,  because  it  is  found  that  these  teeth  have  a  common 
pulp-chamber.  If  the  fusion  occurred  subsequent  to  the  first  deposition 
of  calcic  substances,  the  pulp-chamber  would  be  double.  In  the  period 
of  root-formation  the  common  pericementum  may  or  may  not  be 
divided ;  if  it  is,  the  fused  crowns  are  associated  with  separate  roots ; 
if  not,  the  roots  are  fused  and  have  dentin  common  to  both  throughout. 

Concrescence  of  Teeth. — Concrescence  of  teeth  is  their  union 
after  the  tooth  is  formed ;  it  is  evident,  therefore,  that  the  union  can 
only  be  caused  by  fusion  of  cementum.  This  means  that  at  some  por- 
tion of  the  formative  and  eruptive  period  the  bony  partition  between 
the  teeth  disappears,  and  that  their  pericementi  become  united,  receding 
from  the  line  of  compression  as  cementum  is  deposited  between  and 
joining  the  roots. 

In  the  eruption  of  the  third  molars,  particularly  the  upper,  tem- 
porary lack  of  space  for  the  eruption  of  the  crown  may  cause  absorp- 
tion of  the  bone  covering  the  roots  of  the  second  molar,  and  fusion  of 
the  formative  pericementum  of  the  third  molar  with  that  of  the  second 
occurs  ;  a  deposition  of  cementum  then  binds  the  teeth  together,  prevent- 
ing the  eruption  of  the  third  molar. 

Geminous  Teeth. — These  have  been  termed  twin  teeth,  in  contra- 
distinction to  fused  teeth.     In  twin  teeth  the  enamel-organ,  developed 

Fig.  160.  Fig.  161. 


A-  a 

Fig.  160.— The  upper  molar. 

Fig.  161.— Showing  unusual  development  of  the  cingule  or  basal  talon  on  an  incisor.     (From 
case  reported  hy  W.  H.  Mitchell,  Dental  Cosmos,  vol.  xxxiv.,  p.  2036.) 

from  some  single  cord,  assumes  the  form  of  two  teeth,  and  the  tooth 
developed  in  such  enclosure  has  the  form  of  a  duplicated  prototype.  The 
second  segment  is  to  be  classified  as  a  supernumerary  mass. 


218       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 


Supplemental  Cusps. — It  is  occasionally  observed  that  a  tooth 
has  a  greater  number  of  cusps  than  normal.  The  most  common  form 
of  this  condition  is  a  supplemental  mass  attached  to  the  palatal  side  of 
the  mesio-palatine  cone  of  the  upper  first  molars  (Fig.  160).  The 
palatal  tubercle,  the  prominence  upon  the  cingule  of  an  upper  incisor, 
may  be  of  exaggerated  size.  In  one  case  recorded  (Fig,  161)  this- 
development  gave  the  appearance  of  a  talon  upon  the  tooth,  a  distinct 
cusp-segment  in  itself. 

Malformations  of  Roots. — Differences  in  regard  to  the  size, 
arrangement,  forms,  and  number  of  the  roots  of  teeth  are  the  most 
common  of  dental  malformations.  The  roots  of  teeth  may  be  abnor- 
mally short ;  they  may  be  inordinately  long — roots  of  cuspid  teeth  more 
than  an  inch  in  length  are  by  no  means  uncommon  (Fig.  162).  The  roots 
of  cuspid  teeth  may  be  bifurcated  (Fig.  163),  and  those  of  bicuspids 
trifurcated  (Fig.  164).  The  lower  molars  may  have  three  roots  (Fig. 
165).     Thompson^  has  pointed  out  that  such  malformations,  together 


Fig.  162. 


Fig.  163. 


Fig.  164. 


Fig.  165. 


Upper  cuspids. 


Upper  first  bicuspid. 


Lower  first  molar. 


with  certain  crown  malformations,  are  instances  of  zoological  atavism. 
Abnormalities  of  root-forms  are  of  extreme  frequency.  Examples  of 
these  are  seen  in  Figs.  166-177. 


Fig.  166. 


Fig.  167. 


Fig.  168. 


Fig.  169.        Fig.  170. 


Upper  molars  (Ottolengui). 


Lower  bicuspids. 


Hutchinson  Teeth. — Attention  was  first  called  to,  and  an  ade- 
quate explanation  of  the  condition  given  by  Jonathan  Hutchinson,  as  to 
the  effect  of  hereditary  syphilis  upon  the  permanent  teeth.  He  observed 
in  the  children  of  syphilitic  parents  a  malformation  of  the  anterior 

^  American  Text-book  of  Operative  Dentistry, 


MALFORMATIONS  OF  THE  TEETH. 


219 


teeth,  the  incisors  commonly  and  inconstantly  the  cuspids.     The  situ- 
ation of  these  malformations  is  such  as  to  correspond  to  that  period  of 


Fig.  171. 


Fig.  172. 


Fig.  173. 


Abnormalities  in  teeth. 
Fig.  174.  Fig.  175.  Fig.  176. 


Fig.  177. 


development  when  the  evidences  of  hereditary  syphilis  are  noted  in  the 
infant. 

Confusion  of  description  by  dentists  and  faulty  observation  by 
medical  practitioners  as  to  both  forms,  have  led  to  much  confusion 
as  to  what  particular  forms  of  teeth  are  to  be  regarded  as  syphilitic. 
The  teeth  most  frequently  affected  are  the  upper  central  incisors.  It 
will  be  recalled,  in  this  connection,  that  children  of  syphilitic  parents 
have  usually  a  tardy  eruption  of  the  deciduous  teeth.  The  teeth  have 
a  dull,  opaque  color.  The  central  or  lateral  incisors  upper  and  lower, 
either,  both,  or  any  of  them,  have,  instead  of  the  normal  angles  and 
flattened  curves  of  the  labial  faces,  a  roughly  rounded  and  stunted  ap- 
pearance ;  the  occlusal  edge  of  the  tooth  is  narrower  than  its  neck.  Over 
the  tips  of  these  stunted  and  conical  teeth  the  enamel  is  irregularly  and 
badly  formed ;  but  there  is  a  semblance  of  the  three  enamel-tubercles 
found  normally.  The  middle  tubercle  appears  to  be  of  the  most  defec- 
tive enamel  (Fig.  178),  because  it  is  soon  lost  by  abrasion,  leaving  a 
notch  in  the  tooth  at  its  former  site  (Fig.  179).  While  Hutchinson 
regarded  the  central  incisors  as  the  diagnostic  teeth  of  hereditary 
syphilis,  all  of  the  teeth  undergoing  amelification  at  the  same  time  may 
exhibit  deformities,  one  of  the  most  frequent  being  the  malformation 
of  the  cuspids. 

It  has  been  noted  that  not  all  children  who  are  the  victims  of 
hereditary  syphilis  present  these  dental  appearances ;  and,  again,  ap- 


220       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 


pearances  said  to  be  identical  with  them  are  observed  in  children  said 
not  to  be  syphilitic ;  nevertheless  the  presence  of  such  teeth  is  nsually 
regarded  as  a  valuable  diagnostic  sign  of  hereditary  syphilis.     Thera- 


FiG.  178. 


Fig.  179. 


Syphilitic  teeth  in  upper  and  lower  jaws  as 
they  appear  when  recently  erupted. 


The  teeth  of  hereditary  syphilis 
at  maturity. 


peutic  measures  based  upon  this,  as  well  as  other  doubtful  indications, 
are  followed  by  better  results,  perhaps,  than  when  the  general  indication 
of  the  dental  malformation  is  ignored. 

The  existence  of  interstitial  keratitis  is  accepted  as  additional  diag- 
nostic sign  of  hereditary  syphilis  in  the  infant. 

Odontomes. — In  rare  cases  dental  masses  of  such  irregular  form 
as  almost  to  defy  classification  make  their  appearance  in  the  dental  arch. 
They  may  appear  instead  of  the  teeth,  in  addition  to  them,  or  after 
them  ;  such  masses  may  be  grouped  under  the  head  of  odontomes.  In 
some  instances  they  never  make  their  appearance  in  the  dental  arch, 
but  may  remain  imbedded  in  the  substance  of  the  jaw  for  lengthened 
periods ;  here  they  may  give  rise  to  cyst- formations  (called  odontoceles); 
may  excite  no  evident  reaction,  or  may  be  the  exciting  cause  of  various 
morbid  reactions. 

In  some  instances  the  fusion  of  two  teeth  may  produce  a  mass  of 

such  irregularity  of  form  as  to  give  the  appearance  of  a  dental  tumor, 

but  critical  examination  rarely  fails  to  demonstrate  a  fusion.     Equally 

odd  appearances  may  result   from  the  fusion  of  supernumerary  with 

the  normal  teeth  (Fig.  180).     The  nature  of  these  cases  may  usually  be 

made  out  by  the  more  or  less 
Fig.  180.  Fig.  181.  ,     ,  ,     ^ 

orderly  arrangement  oi  cemen- 

tum  and  enamel  (Fig.  181). 
A  specimen  (Fig.  182)  in  the 
museum  of  the  Academy  of 
Stomatology  of  Philadelphia, 
shows  two  masses  making  their 
advent  between  the  upper  cen- 
tral incisor  teeth,  forcing  these 
teeth  aside.  From  the  appearance  of  the  surfaces  of  these  masses  they 
represent  the  results  of  a  plication  of  the  surface  of  the  enamel-organ  from 


A  supernumerary  tooth  attached 
to  the  roots  of  an  upper  molar, 
the  supernumerary  tooth  being 
inverted.    (Smale  and  Colyer.) 


3rAL FORMATIONS  OF  THE  TEETH. 


221 


which  they  derived  their  enamel.    Clearly  they  are  tlie  results  of  the  for- 
mation of  two  adventitious  dental  cords.     Fig.  183  illustrates  an  odon- 

FiG.  182. 


Fio.  183. 


toma  in  which  the  dental  nature  of  the  growth  is  to  be  clearly  made 
out;  the  enamel-forming  organ  from  which  the  mass  derived  its  enamel- 
cup  was  of  anomalous  form.  Such  specimens  are  known  as  warty  teeth 
(Salter). 

Broca^  was  the  first  to  offer  a  systematic  classification  of  tooth- 
tumors,  although  the  connection  between  various  tumor  types  and  dental 
tissues  had  long  before  been  made  out. 

The  discussion  of  the  pathogenesis,  clinical  history,  and  treatment  of 
odontomes  which  arise  from  some  portion  of  the  tooth-follicle  in  its 
embrj^onic  state  and  cause  the  formation  of  exten- 
sive neoplastic  growths  which  bear  no  resemlilance 
to  tooth-forms,  their  only  points  of  association 
being  scattered  histological  appearances,  belongs  to 
the  province  of  general  surgical  pathology,  and 
their  treatment  to  general  or  special  surgery,  so  that 
they  can  be  fitly  dismissed  from  these  pages  with  a 
brief  mention. 

A  developed  tooth-follicle  contains  within  it 
both  epiblastic  (epithelial)  and  mesoblastic  (con- 
nective) tissue-elements.  An  aberrant,  morbid  tissue-development  may, 
therefore,  give  rise  to  either  epithelial  or  connective-tissue  new  forma- 
tions, the  cellular  elements  of  which  may  be  of  an  embryonic  (sarco- 
matous) or  mature  (fibromatous,  osteomatous,  etc.)  type  ;  or  may  be  the 
starting-point  of  either  comparatively  benign  epithelial  growths  or  even 
of  carcinoma.     The  growth  may  contain  the  elements  of  several  types 

^  Recherches  sur  une  nouveau  groiipe  de  tnmeuvs  designe  sous  le  nom  d' odontomes,  1867. 


Odontoma.  (Garretson.) 


222       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 


combined.  It  appears  that  cyst-formation  most  commonly  results  from 
a  continued  collection  of  fluid  between  the  epithelial  coating  of  a  tooth- 
follicle  and  the  dentinal  and  enamel  elements  underlying,  the  accumula- 
tion of  fluid  causing  the  formation  of  a  sac  lined  by  the  transformed 
epithelial  wall. 

Odontomata  of  direct   clinical   interest  to   the   dental   practitioner 
are  those  connected  with  some  portion  of  a  tooth,  showing  an  irreg- 
ular or  anomalous  growth  of  some  one  or  more  of  the  dental  tissues. 
Fig.  184.     Fig.  185.  Fig.  186. 


Enamel  excrescences.    (Salter.)  Results  of  hernia  of  a  pulp.    (Salter.) 

Many  of  these  may  be  and  have  been  classified  under  the  head  of  mal- 
formations of  the  teeth.  Many  of  the  surgical  odontomata  exhibit  but 
slight  trace  of  any  dental  structure,  but  in  the  class  under  discussion  it  is 

Fig.  187. 


Fig.  186  magnified. 


evident  that  a  continuous  relationship  has  been  kept  between  an  enamel- 
organ,  a  dentinal  pulp,  and  a  cementoblastic  structure,  even  though  the 
aberrations  of  tooth-form  and   of  limitations  as  to  extent  of  growth 


MALFORMATIONS  OF  THE  TEETH. 


223 


diverge  widely  from  the  normal.  In  some  of  these  growths  it  is 
evident  that  tooth-development  has  })rogressed  in  an  orderly  manner  to 
a  varying  degree  before  any  aberration  of  development  occurred  ;  in 
others  it  is  evident  that  development  has  been  aberrant  from  the 
beginning. 

The  growth  may  be  associated  with  enamel,  dentin,  or  cementnm 
development ;  and  its  tissue-elements  as  regards  the  dentin  may  remain 
normal,  or  may  occasionally  partially  revert  to  other  types,  vaso- 
dentin, osteodentin,  etc.  Figs.  184  and  185  exhibit  the  results  of 
activity  of  the  enamel-organ  continued  after  its  normal  formative  period 
and  in  an  irregular  manner. 

The  development  of  both  enamel  and  dentin  may  proceed  in  an 
orderly  manner  for  some  time,  when  an  irregular  developmental  impulse 
arises  in  the  dentinal  pulp,  leading  to  its  enlargement  and  extension 
beyond  the  enamel-organ,  which  latter  structure  suffers  atrophy,  and  a 
growth  of  the  following  type  results.  The  pulp  outgrowth  may  not 
occur  until  both  crown  and  root  of  the  tooth  have 
been  formed  in  an  orderly  manner,  when  a  hyper- 
trophic impulse  causes  this  organ  to  extend  far 
beyond  its  normal  boundaries,  still,  however,  en- 
closed in  the  follicular  wall ;  the  pulp  in  its  new 
relations  deposits  dentin,  over  which  cementum  is 
deposited  (Figs.  188,  189,  and  190). 

Fig.  188. 


Fig.  189. 


Figs.  18S  auU  isy.— Kesults  of  pulp-hernia.    (Tomes.) 

Neither  the  enamel-organ  nor  dentin-pulp  may  assume  its  normal 
type,  and  yet  the  relationship  between  the  epithelial  tissue  of  the 
enamel-organ  and  a  layer  of  odontoblastic  cells  in  the  underlying  meso- 
blastic  tissue  is  maintained,  together  with  a  general  enclosure  in  a 
follicular  wall,  in  which  event  an  irregular  mass  (see  Fig.  183,  warty 
tooth)  containing  the  dental  elements  is  formed. 

Irregularity  of  growth  is  undoubtedly  more  frequently  associated 
with  the  cementum  than  with  any  other  dental  tissue.  It  may  assume 
the  form  of  a  generally  excessive  deposit,  be  in  the  form  of  a  nodu]-? 
or  nodules,  or  be  a  large  irregular  mass. 

Teeatment. — The  treatment  of  these  cases  is  that  applied  to  all 


224       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

removable  tumors — radical  extirpation.     While  in  some  cases  this  con- 
sists of  the  operation  of  tooth-extraction  on  a  large  scale^  in  others  the 

Fig.  190. 


A  section  of  Fig.  189  through  A  B. 


removal  of  an  odontome  involves  the  performance  of  a  surgical  opera- 
tion of  some  magnitude. 

Anomalies  of  Number. — Although  the  dental  series  of  man  nor- 
mally consists  of  thirty-two  members,  cases  are  frequently  observed 
where  the  number  is  in  excess  of  or  less  than  that  number. 

Deficiency. — It  is  observed  with  some  frequency  that  the  upper 
lateral  incisors  of  a  denture  never  make  their  appearance,  a  condition 
traceable  to  the  influence  of  heredity  in  some  of  the  instances.  The 
permanent  cuspids  erupt  and  occupy  the  lateral  incisor  space.  The 
third  molars  may  never  appear ;  instead  of  being  represented  by  a  rudi- 
mentary tooth,  they  are  apparently  never  formed.  There  is  no  doubt 
that  in  some  of  the  cases  of  apparent  absence  of  the  third  molars  that  the 
teeth  may  be  encysted  in  the  maxillae ;  but  when  none  of  them  appear 
up  to  the  age  of  forty  years  it  is  a  fair  inference  that  they  have  not 
been  formed.  The  writer  has  seen  an  upper  third  molar  erupting  at 
the  age  of  sixty.  The  cases  of  suppressed  teeth  next  in  point  of  fre- 
quency are  those  of  the  bicuspid  teeth.  If,  however,  the  corresponding 
teeth  are  all  present  in  the  dental  arch,  a  well-founded  suspicion  of 
impaction  of  the  missing  tooth  may  be  entertained. 

The  extreme  of  suppressed  formation  is  represented  in  a  case  de- 
scribed by  Guilford.^  A  patient  over  fifty  years  old  had  never  erupted 
any  teeth,  deciduous  or  permanent ;  the  alveolar  arches  revealed  no  evi- 
dences of  enclosed  teeth,  but  had  the  appearance  of  typical  edentulous 
jaws  ;  the  alveolar  bone  itself  was  primitive.     The  case  appeared  to  be 

^  American  System  of  Dentistry^  vol.  iii. 


MALFORMATIONS  OF  THE  TEETH.  225 

sporadically  hereditary,  a  grandparent  and  an  uncle  exhibiting  a  like 
condition.  The  cases  are  interesting  also  because  of  additional  evidences 
of  faulty  evolution  of  dermoid  structures.  In  the  first  case  cited  no 
sudoriparous  glands  appear  to  have  formed,  and  there  was  but  a  faint 
growth  of  hair  on  the  cranium,  and  none  on  the  face  and  body.  The 
uncle  was  hairless  and  edentulous  from  birth.  Guilford  found  in  other 
members  of  the  family  an  absence  of  the  full  complement  of  teeth. 

Excess. — The  possible  occurrence  of  a  condition  in  some  respects  the 
reverse  of  the  preceding  has  been  much  written  of  and  discussed — /.  e., 
the  occurrence  of  a  complete  third  denture.  There  can  be  but  one  con- 
clusion from  an  examination  of  all  the  evidence  thus  far  presented,  and 
that  is  that  no  clear  and  well-authenticated  cases  are  made  out.  Isolated 
cases  of  the  appearance  of  teeth  subsequent  to  the  loss  of  all  of  the  sec- 
ond denture  are  not  infrequent ;  and,  so  far  as  clear  records  can  be  ob- 
tained, ai-e  resolvable  into  cases  of  the  eruption  of  supernumerary  teeth. 
While  these  cases  are,  at  least  for  the  present,  to  be  held  as  unproved  in 
connection  with  elderly  persons,  a  well-authenticated  case  of  multiple  den- 
tition in  a  child  is  recorded  by  Catching.^  Between  the  sixth  and  the  sev- 
enth month  the  eruption  of  one  set  of  teeth  was  complete ;  within  three 
months  all  of  these  had  been  lost.  Between  the  eleventh  and  fifteenth 
months  another  period  of  dentition  occurred,  the  teeth  of  this  second 
denture  being  of  such  faulty  structure  as  to  crumble  away  quickly.  At 
the  age  of  two  and  one-half  years  a  third  dentition  appeared,  which 
caused  the  child  such  inconvenience  that  the  teeth  were  extracted  by 
the  mother.  At  the  age  of  eleven  years  a  fourth  series  erupted,  incom- 
plete through  the  absence  of  six  teeth.  At  the  age  of  fifteen  these  teeth 
were  sound  and  firm. 

Fourth  Molar. — The  molar  series  of  man,  particularly  in  the 
lower  negroid  races,  may  consist  of  four  instead  of  three  members. 
"When  the  fourth  molar  appears  in  the  white  races  it  is  usually  as  a 
stunted  member,  a  conical  or  peg-like  tooth,  similar  to  that  which  oc- 
casionally replaces  the  third  molar.  There  is  rarely  room  posterior  to 
the  distal  wall  of  the  third  molar  for  their  eruption,  so  that  they  make 
their  appearance  in  the  region  shown  in  the  illustration.  S.  M.  Hart- 
man,-  L.  D.  S.,  of  Victoria,  B.  C,  has  furnished  the  model  (Fig.  191) 
of  a  case  where  the  molar  form  of  the  fourth  tooth  is  unusually  well 
pronounced. 

Supernumerary  Teeth. — Any  teeth  in  excess  of  the  normal 
thirty-two,  although  clearly  cases  of  reversion  of  type  in  many  in- 
stances,^ are  included  in  the  category  of  supernumerary  teeth.     Super- 

1  Southern  Dental  Journal,  Oct.,  1886.  ^  Dental  CosviO!<,  1891. 

•^  A.  H.  Thompson,  American   System   of    Dentistry,  vol.  iii.,  and   Kirk's    Operative 
Dentistry. 
15 


226       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 


uumeraiy  teeth  appear  as  simple  unmodified  cones,  or  as  combinations 
of  cones  resembling  the  forms  of  teeth.  The  conical  form  is  most 
common.  Cases  where  these  peg-like  teeth  appear  around  the  third 
molars  singly  or  in  number  are  numerous.     Their  appearance  in  any 

Fig.  191. 


situation  is  evidence  that  the  normal  number  of  dental  cords  has  been 
exceeded.  They  are  perhaps  all  to  be  regarded  as  cases  of  long  rever- 
sion, not  alone  because  they  increase  the  number  of  the  dental  series, 


Fig.  192. 


(  . 


but  because  they  have  primitive  forms,  a  modification  of  the  forms 
found  among  the  reptiles  and  fishes. 

Guilford^   divides  supernumerary  teeth  into  those  having  typical 
anatomical  forms  and  those  having  the  conical  form. 

^  American  System  of  Dentistry,  vol.  iii. 


MALPOSITIONS  OF  THE  TEETH.  227 

Supernumerary  incisors  in  either  jaw  having  typical  forms  are  not 
uncommon.  In  the  upper  jaw  supernumerary  centrals  and  laterals 
both  appear,  the  latter  more  frequently  (Fig.  192).  Supernumerary 
teeth  may  occupy  any  position  relative  to  the  dental  arch,  but  are  more 
frequently  seen  at  its  lingual  side.  The  compound  cone  occasionally 
appears  (Fig.  193).  In  addition  to  molars  and  incisors, 
supernumerary  bicuspids  are  occasionally  found ;  super- 
numerary cuspids  are  very  rare. 

Unless  supernumerary  teeth  are  a  source  of  offence 
either  through  their  positions  or  appearance,  they  need 
not  be  disturbed.  If  they  are  found  to  be  so,  they  may 
be  extracted. 

Malpositions  of  the  Teeth. 

A  tooth  is  said  to  be  in  malposition  when  it  is  not  in  normal  relation 
with  the  dental  arch  to  which  it  belongs  and  to  its  antagonizing  teeth 
of  the  opposing  arch.  Teeth  are  found  in  abnormal  positions  as  the 
result  of  a  variety  of  causes.  Some  of  these  operate  prior  to,  during, 
or  immediately  after  eruption  ;  some  long  after  the  eruption  of  the  teeth, 
and  some  because  of  non-eruption. 

Malpositions  which  are  remediable  through  the  application  of  me- 
chanical force  applied  by  means  of  suitable  apparatus  belong  to  ope- 
rative dentistry,  as  has  been  stated.  They  are  fully  treated  of  in  works 
upon  operative  dentistry  ^  and  orthodontia,^  so  that  their  discussion  in  a 
treatise  upon  pathology  might  seem  a  work  of  supererogation  ;  the  plan 
of  the  book,  however,  demands  their  brief  mention. 

Malposed  teeth  may  occupy  any  position  relative  to  the  dental  arch, 
and  anv  teeth  of  the  dental  series  mav  be  the  offenders,  although  most 
commonly  noted  in  connection  with  the  incisors.  So  common  is  some 
degree  of  irregularity  of  the  position  of  the  lower  incisors  that  its  appear- 
ance is  scarcely  regarded  as  abnormal.  The  teeth  may  be  inside  or 
outside  the  dental  arch,  or  have  their  transverse  axes  at  any  angle  with 
the  arch  line — i.  e.,  may  be  rotated  in  any  manner.  In  the  most  ag- 
gravated cases  an  entire  half  denture  may  be  malposed  as  regards  its 
relations  with  the  opposing  or  antagonizing  half.  Instead  of  having 
the  upper  teeth  occluding  outside  the  lower,  they  may  occlude  inside 
(Fig.  194).  They  may  occlude  squarely  without  incisor  overlapping. 
Both  of  these  abnormal  conditions  are,  of  course,  due  to  lack  of  corre- 
spondence between  the  development  of  the  lower  and  upper  jaws.  If 
one  jaw  has  developed  normally,  the  other  has  necessarily  developed 
insufficiently  or  too  much. 

^  American  Text-book  of  Operative  Dentistry. 
^Guilford,  Orthodontia;  Angle  and  others. 


228       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

Malpositions  of  entire  groups  of  teeth  are  found  attended  by  an 
insufficient  development  of  the  alveolar  bone  of  that  region.  They 
may  also  be  caused  by  an  excessive  development  of  some  section  of  the 
alveolar  bone.     The  underlying  causes  of  these  gross  aberrations  are 

Fig.  194. 


only  imperfectly  made  out.  The  reasoning  adopted  in  discussing  their 
causes  and  the  conclusions  reached  appear  to  be  largely  speculative, 
although  some  of  them  are  plausible.  (The  reader  is  referred  to  mon- 
ographs upon  orthodontia  for  the  full  discussion  of  these  matters.) 


CAUSES    OF   MALPOSITIONS. 

The  causes  for  the  malpositions  of  individual  teeth  are  frequently 
traceable  with  a  reasonable  degree  of  certainty.  The  upper  lateral  in- 
cisor has  an  inherent  disposition  to  erupt  inside  the  dental  arch  ;  its 
crown  during  the  formative  stage  lies  slightly  behind  the  crowns  of  the 
cuspid  and  central  incisor ;  again,  the  forms  of  the  alveoli  of  the  tem- 
porary teeth,  if  regarded  as  rounded  triangles  on  section,  have  the  bases 
of  the  triangles  of  cuspid  and  central  incisor  outward,  while  the  base 
of  the  triangle  of  the  lateral  incisor  is  inward,  hence  a  line  inward  to 
the  arch  is  the  direction  the  crown  of  the  lateral  incisor  tends  to  follow. 
Erupting  normally,  this  tooth  has  a  disposition  to  cause  outward  dis- 
placement of  the  cuspid.  The  lower  incisors,  held  in  an  arch  by  the 
nature  of  the  occlusion  of  the  upper  teeth,  and  no  doubt  also  by  the 
tongue,  have  not  the  same  freedom  of  alteration  of  position  as  have 
the  upper  teeth ;  hence  when  the  larger  permanent  teeth  replace  the 
smaller  deciduous  teeth  they  are  crowded  in  the  same  arch-space  and 
malposition  results.  It  is  evident  that  comparatively  slight  forces  may 
deflect  the  direction  of  eruption  of  teeth,  as  they  are  only  partially 
formed  at  the  eruptive  period,  and  are  loosely  enclosed. 

Effects  of  Extraction  of  Deciduous  Teeth. — The  effects  of  the 
extraction  of  the  deciduous  teeth  largely  depend  upon  the  time  at  which 


MALPOSITIONS  OF  THE  TEETH.  229 

the  extraction  is  done.  The  general  effect  of  extraction  of  the  tempo- 
rary teeth  before  their  permanent  snccessors  are  ready  or  nearly  ready 
to  occnpy  their  places  is  a  lack  of  space  for  the  accommodation  of  the 
permanent  successor,  causing  a  delay  in  its  eruption.  The  extrac- 
tion of  a  temporary  tooth  interferes  not  only  with  those  formative 
chano-es  in  the  alveolar  bone  Avhich  afford  increased  space  for  the  suc- 
ceeding permanent  tooth,  but  interferes  also  with  the  resorptive  process 
which  frees  the  permanent  tooth  from  the  roof  of  its  cavity.  An 
additional  feature  is  the  usual  narrowing  of  the  space  from  which  the 
tooth  has  been  removed.  These  conditions  are  more  clearly  observable 
in  the  case  of  the  too  early  extraction  of  the  temporary  second  molars. 
Not  infrequently  these  teeth  are  extracted  prior  to  the  seventh  year,  or 
even  earlier.  Four  vears  or  thereabouts  must  then  elapse  before  the 
permanent  successor  makes  its  appearance.  The  crown  of  the  latter 
lies  in  the  base  of  the  alveolar  bone,  covered  upon  all 
sides  by  bony  walls,  and  its  position  is  lo\ver  than  ^^*^-  ^^'^• 

the  roots  of  the  adjoining  teeth,  the  temporary  first 
and  permanent  first  molar.  The  normal  tendency 
of  the  latter  tooth  is  forward,  and  in  the  absence 
of  the  second  molar  it  may  attain  a  position  imme- 
diately contiguous  to  the  posterior  surface  of  the 
first  temporary  molar.  If  the  extraction  occurs 
before  the  eruption  of  the  ]ierraanent  first  molar, 
the  condition  described  is  almost  certain  to  obtain.     Effects  of  the  premature 

1  111  •li?  i'l-j.!  1  loss    of   a   deciduous 

hence  when  the  period  of  eruption  for  the  second  second  molar. 
bicuspid  arrives,  the  tooth  is  compelled  to  take  a 
direction  inward  or  outward  of  the  dental  arch,  or,  as  happens  in  some 
cases,  the  tooth  does  not  eru])t  at  all,  but  remains  impacted  or  encysted. 
Similar  effects  may  be  noted  in  connection  with  the  remaining  anterior 
teeth.  The  injury  caused  by  extraction  has  been  said  to  interfere  with 
the  normal  formative  processes  occurring  in  the  follicle  of  the  corre- 
sponding permanent  tooth.  Such  an  effect  is  not  at  all  improbable. 
Effects  of  Delayed  Loss  of  Deciduous  Teeth. — If  the  resorption 
of  the  roots  of  the  temporary  teeth  does  not  keep  pace  with  the  advance  of 
the  permanent  teeth,  more  or  less  deflection  of  the  course  of  the  latter  is 
almost  certain  to  ensue.  Recognizing  the  positions  of  the  crowns  of 
erupting  anterior  permanent  teeth  in  relation  with  the  roots  of  the  ante- 
rior temporary  teeth,  it  is  evident  that  the  general  teudency  of  faulty 
eruption  in  these  cases  is  inward.  Comparatively  and  actually  slight 
forces  may  deflect  the  course  of  an  erupting  tooth,  hence  the  lower 
incisors,  erupting  before  the  upper,  even  though  inward  of  the  arch, 
are  frequently  driven  into  the  arch-line  by  the  muscular  force  of  the 
tongue ;  the  upper  incisors,  erupting  later  and  iiiAvard,  are  imprisoned 


230       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

by  the  lower  incisors.     It  needs  but  the  contact  of  slight  occlusion  to 
transform  a  slight  into  a  marked  malposition. 

A  curious  relationship  is  sometimes  established  through  the  long 
retention  of  a  temporary  molar  :  the  alveolar  process  develops  normally 
and  carries  with  it  bodily  the  retained  temporary  tooth  to  a  higher  level, 
to  the  same  level  occupied  by  adjoining  teeth,  so  that  the  tooth  is  in 
correct  occlusion,  although  raised  far  beyond  its  original  level.  The 
eruptive  impulse  of  the  permanent  successor  of  such  retained  temporary 
teeth  seems  to  exhaust  itself  without  avail,  and  the  temporary  tooth 
remains  as  a  permanent  feature  of  the  adult  denture. 

Treatment. — When  it  is  evident  that  the  presence  of  a  temporary 
tooth  has  deflected  the  line  of  eruption  of  its  permanent  successor  it 
should  be  removed.  When  temporary  teeth  are  retained  beyond  the 
normal  period  of  eruption  of  their  successors  some  operators  advise  that 
they  should  be  extracted,  a  procedure  said  by  them  to  hasten  the  appear- 
ance of  the  permanent  successors.  This  rule  is  too  sweeping,  for  erup- 
tion may  be  delayed  from  a  variety  of  but  partially  understood  causes, 
and  the  violence  of  extraction  may  disturb  instead  of  aid  eruption. 
However,  when  there  is  a  pulpless  temporary  tooth  in  the  arch,  and  all 
of  the  corresponding  permanent  teeth  are  in  position,  the  indication  is  to 
extract  the  pulpless  tooth.  The  process  of  resorption  is  faulty  and  in- 
complete in  such  cases,  and  it  is  probable  that  the  extraction  of  the  tooth 
removes  a  mechanical  obstruction  to  the  eruption  of  its  successor.  In 
the  absence  of  an  appearance  of  the  crown  of  a  permanent  tooth,  and 
with  no  evidences  of  loosening  of  the  healthy  temporary  tooth,  the 
forcible  extraction  of  the  latter  is  rarely  advisable.  It  has  happened 
that  firm  and  sightly  temporary  teeth  have  been  extracted,  but  no  per- 
manent successor  appeared. 

Effects  of  the  Early  Extraction  of  the   Perma- 
nent First  Molar. — The  permanent  first  molar  erupted 
from  the  sixth  to  the  eighth  year  may  suffer  from  dental 
caries,  pulp-necrosis,  or  alveolar  abscess  before  the  tenth 
or  eleventh  year.     If  these  teeth  are  extracted,  a  char- 
acteristic dental  deformity  follows.     Recalling  that  the 
development  of  the  jaw  proceeds  in  such  manner  that 
the  depth  of  the  alveolar  bone   is  constantly  increasing 
until    adult    age,  and    that    this    development  is    only 
marked  during  and  after  the  appearance  of  the  second 
^^ureiofsofTer-      dentition,  it  is  evident  that  the  extraction  of  the  per- 
manent first  mo-      manent  first  molar  is  followed  by  a  lessenina:  or  cessation 
of  development  of  the  bone  adjacent ;  the  formative  pro- 
cess will  not  then  deepen  the  lateral  alveolar  walls  until  the  period  of 
eruption  of  the  bicuspids,  not  for  three  years  or  more.     In  the  mean- 


MALPOSITIONS  OF  THE  TEETH.  231 

time  the  permanent  incisors  erupt  and  the  alveolar  bone  deepens 
around  them  ;  their  occlusion  is  not  limited  in  extent  by  a  corre- 
sponding deepening  of  the  posterior  alveolar  bone.  The  lower  in- 
cisors, being  without  check  to  their  action,  come  to  strike  the  upper 
incisors  at  their  cervico-palatine  portions  ;  these  latter  teeth  are  gradu- 
ally driven  from  their  vertical  positions  until  they  assume  almost  a  hori- 
zontal direction. 

Treatment. — The  treatment  of  this  condition  is  i)reventative  :  the 
permanent  first  molars  should  not  be  extracted  until  the  bicuspids 
have  fully  erupted,  provided  that  their  retention  is  possible.  The  perma- 
nent first  molars,  far  from  being,  as  was  once  held,  the  most  worthless 
teeth  of  the  dental  series,  are  the  most  important.  Their  eruption  at  an 
early  period  is  a  distinct  indication  of  the  important  influence  their  pres- 
ence exerts  upon  the  normal  development  of  the  alveolar  bone  about  and 
posterior  to  them.  Their  eruption  is  about  synchronous  with  the  com- 
pletion of  the  evolution  of  the  alimentary  canal  and  its  appendages ; 
hence  their  office  in  the  increased  mastication,  normal  at  this  time,  is 
clear ;  their  presence  beyond  a  doubt  determines  the  extent  of  the  for- 
mative process  which  shall  occur  in  the  alveolar  bone  posterior  to  them. 
From  the  period  of  their  eruption  they  should  be  carefully  scrutinized ; 
and  even  though  caries  and  subsequent  disease-processes  act  to  the  ex- 
tent of  alveolar  abscess,  the  conditions  are  to  be  vigorously  treated,  so 
that  the  teeth  may  be  retained  until  after  the  eruption  of  the  second 
bicuspids. 

IMPACTED  AND  ENCYSTED  TEETH. 

The  extreme  extent  of  dental  malposition  is  reached  when  the  perma- 
nent teeth  do  not  erupt  at  all.  Instead  of  presenting  in  the  dental  arch, 
they  may  be  entirely  imbedded  in  the  substance  of  the  bone,  either  re- 
maining there,  with  or  without  pathological  manifestations,  or  erupting 
in  some  very  unusual  situation.  In  other  cases  a  distinct  cystic  tumor 
forms  about  the  enclosed  tooth. 

Impacted  Lo-wer  Third  Molars. — By  far  the  most  common  dental 
impaction  is  that  of  the  lower  third  molar.  The  extent  of  impaction 
varies  from  a  partial  eruption,  or  partial  imprisonment  of  the  tooth  by 
its  bony  surroundings,  to  its  entire  imprisonment  in  any  part  of  the 
maxilla.  Many  of  the  more  severe  cases  treated  of  under  the  head  of 
difficult  eruption,  if  unrelieved  would  be  included  in  the  category  of 
impacted  teeth. 

In  Fig.  197  is  shown  a  lower  third  molar  presenting  the  effects  of  a 
previous  impaction.  The  irritation  caused  by  the  efforts  of  the  tooth  to 
disengage  itself  or  to  overcome  the  resistance  to  its  eruption  has  caused 
an  active  formative  reaction  in  the  pericementum,  resulting  in  a  hyper- 
trophy of  the  cementum. 


232       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

If  the  distance  between  the  ]:)Osterior  surface  of  the  second  molar 
and  the  cokunns  of  the  coronoid  process  be  very  short,  it  is  evident  that 
upward  eruption  is  impossible,  so  that  the  tooth  may  assume  any  direc- 
tion of  movement,  the  most  common  being  forward,  the  axis  of  the  tooth 


Fig.  197. 


Right  half  of  lower  jaw,  showing  an  impacted  third  molar.     (.Cryer.) 
Fig.  198. 


Inner  side  of  left  half  of  same  lower  jaw.     (Cryer.) 


changing  its  position  until  the  tooth  may  lie  in  a  liorizontal  position  or 
even  become  inverted. 

Fig.  198  is  taken  from  the  same  jaw  as  Fig,  197,  but  shows  the 
opposite  side ;  the  impaction  is  pronounced.     Fig.  199  shows  another 


MALPOSITIOXS  OF  THE  TEETH. 


233 


case  with  different  aniitomical  siirrountlings.  In  the  first  case  there  were 
evidences  both  in  the  tooth,  in  its  bony  surroundings,  and  in  the  exter- 
nal cortical  bone,  of  the  results  of  the  irritation  produced  bv  the  efforts 
at  eruption.     The  cementum  was  thickened  ;  the  outer  follicular  wall, 


Fig.  199. 


(Cryer.) 

the  tissue  designed  to  form  the  alveolar  periosteum,  had  exercised  its 
formative  osteogenetic  function,  and  a  capsule  of  bone  liad  formed  al)out 
the  tooth  ;  it  lay  in  a  bony  chamber.  The  pressure  exerted  upon  the 
distal  wall  of  the  second  molar  had  rc-ulted  in  a  pressure-resorption  of 
its  root  until  the  pulp-chamber  was  encroached  upon.     In  Fig.  199  the 


234       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

root-development  has  caused  impingement  of  the  root-apex  upon  the 
inferior  dental  canal.  These  were  both  post-mortem  cases,  and  no 
records  of  their  clinical  histories  were  obtainable.  The  symptoms 
produced  could  only  be  surmised  by  the  nature  of  the  anatomical  rela- 
tions and  the  pathological  evidences.  There  may  have  been  a  prolonged 
but  mild  periostitis,  probably  a  continued  pulp-irritation ;  and  in  the 
last,  neuralgia  of  any  grade  of  severity. 

Fig.  201. 


Wisdom-teeth  imbedded  in  the  rami  of  the  lower  jaw.    (Tomes.) 

Judging  from  post-mortem  records,  cases  of  impacted  third  molars 
are  more  common  than  generally  believed.     Instead  of  remaining  in 

Fifi.  202. 


Wisdom.-tooth  buried  in  the  ramus.     (Tomes,  after  Marshall.) 


the  alveolar  portion  of  the  bone,  the  impacted  tooth  may  come  to  oc- 
cupy a  cavity  in  some  portion  of  the  body  or  the  ramus  of  the  bone 
(Figs.  201  and  202).     The  positions  of  the  teeth  in  such  cases  tend  to 


MALPOSITIONS  OF  THE   TEETH. 


235 


confirm  Tomes'  theory  of  the  development  of  the  j;i\v.  The  jaw  bein<^ 
lengtliened,  and  the  ramus  developing  through  eonjoined  deposition  and 
resorption  of  bone,  the  crown  of  the  tooth  appears  to  l)e  either  fixed  in 
a  bony  nueleus  and  transported  to  some  distant  ])oint  in  the  develop- 
mental progress  of  the  jaw,  or  to  be  irregularly  shifted  about  during 
jaw-growth.  At  later  periods  the  pressure  exercised  by  root-formati(^n 
disturbs  the  relations  of  tiie  tooth  with  its  earlier  surroundings.  These 
efforts  at  eruption  may  at  late  periods  cause  the  apj)earancc  of  the 
tooth  in  odd  situations  (Fig.  203).      The  crown  of  the  tooth  in  this 

Fig.  203. 


From  a  wax  model  in  the  museum  of  the  London  Odontological  Society.    (Tomes.) 

case  made  its  way  through  the  angle  of  the  bone  and  through  the 
muscles  and  skin.  The  opening  in  the  skin  healed  upon  extraction 
of  the  tooth. 

Impacted  Upper  Third  Molars. — Some  grades  of  imjmction  of  this 
tooth  have  been  spoken  of  under  the  head  of  difficult  dentition.     The 

Fig.  204. 


Upper  jaw,  with  the  third  molar  directed  forward,  and  impinsinc;  upon  the  second  molar.  The 
small  tooth  situated  high  up  in  the  anterior  part  of  the  jaw,  was  furced  there  by  the  spade  of 
the  grave-digger.  The  artist's  accuracy  in  delineatiug  all  parts  of  the  specimen  has  rendered 
this  explanation  necessary.    (Tomes.) 


most  common  is  imprisonment  of  the  tooth  and  its  subsequent  partial 
eruption  in  a  horizontal  position,  the  crown  pointing  toward  the  cheek 
(Fig.  204).     The  crown  of  this  tooth  may  in  rare  cases  be  directed 


236       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 


Fig.  205. 


inward  or  b«(ckward,  in  the  latter  case  being  arrested  by  the  pterygoid 
plates  of  the  sphenoid  bone. 

In  a  case  recorded  by  Tomes  (Fig.  205)  the  extraction  of  the  second 
molar  revealed  the  third  molar  in  a  reversed  posi- 
tion, its  roots  occupying  the  depression  between  the 
roots  of  the  second  molar. 

Impacted  Cuspids. — In  point  of  frequency  of 
impaction  the  upper  cuspids  stand  next  to  the  lower 
third  molars.  It  will  be  recalled  that  the  upper 
cuspids  lie  high  up  ;  the  floors  of  their  crypts,  in 
which  they  lie  loosely,  are  at  a  higher  level  than 
those  of  the  adjoining  teeth  ;  they  erupt  at  a  much 
later  period,  and  their  crowns,  as  with  the  other 
anterior  teeth,  lie  inside  the  roots  of  their  predeces- 
sors. All  of  these  are  elements  which  might  cause 
displacement  of  the  developing  cuspids.  Should  the  advance  of  erup- 
tion not  keep  pace  with  the  development  of  the  alveolar  bone,  impris- 
onment is  likely ;  again,  the  dense  bone  immediately  about  the  first 
bicuspid  aud  lateral  incisor  may  offer  a  deflecting  resistance.  Exam- 
ining the  texture  of  the  bone  about  these  parts,  it  is  evident  that 
the  least  resistance  to  the  advance  of  a  much-deflected  crown  is  into 
the  cancellated  bone    of  the  incisor  portion  of   the  alveolar  process ; 


A  second  molar  of  the 
upper  jaw,  with  the 
wisdom-tooth  invert- 
ed and  embraced  with- 
in the  roots.   (Tomes.) 


Fig.  206. 


Abnormal  jaw,  showing  impjacted  cuspids.    (Cryer.) 


hence  it  is  most  usual  to  find  the  crowns  of  these  teeth  lying  with  their 
cusp-point  forward  (Fig.  206).  Several  recorded  cases  have  the  posi- 
tions shown  ;  one  or  both  of  the  teeth  may  be  encysted. 

Impaction  of  Other  Teeth. — AVhile  impactions  are  most  common 


MALPOSITIONS  OF  THE  TEETH. 


237 


in  connection  with  the  teeth  named,  any  other  teeth  of  a  denture 
mav  be  imprisoned.  Fig.  207  shows  an  imprisoned  bicuspid  whose 
root-development  has  been  normal  as  regards  its  length,  but  whose 


Fig.  207. 


Impacted  bicuspid.    (Salter.) 


curve  has  been  modified  by  the  resistance  of  surrounding  tissues.    Figs. 
208  and  209  exhibit  an  impacted  central  incisor,  whose  retention  was, 


Fig.  209. 


Fig.  208 


Imprisoned  central  im. 


and  Crver.^ 


no  doubt,  determined  and  malposition  caused  bv  the  development 
and  presence  of  the  brood  of  supernumerary  teeth  which  surround  its 
crown. 


238       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

Symptoms. — The  most  common  symptom  attendant  upon  impaction 
of  teeth,  judging  from  the  obtainable  records  of  cases,  is  trifacial  neur- 
algia of  any  degree,  caused  by  impingement  of  the  malposed  tooth 

Fig.  210. 


Lower  maxilla,  in  which  the  right  second  bicuspid  is  placed  obliquely,  the  root  being  directed 
backward.  The  crown,  though  exposed,  does  not  rise  above  the  level  of  the  alveolar  margin.. 
(Tomes.) 

Fig.  211. 


Maxilla,  in  which  the  temporary  cuspids  (the  sockets  of  which  are  shown  by  the  dotted  lines)  were 
retained,  and  the  permanent  canines  developed  within  the  substance  of  the  jaw.  The  bone 
has  been  removed  on  the  one  side  to  show  the  direction  taken  by  the  tooth,  which  has  been 
twisted  on  its  axis  to  the  extent  of  a  quarter  of  a  turn.    (Tomes.) 


Fig.  212. 


upon  nerve-filaments  or  trunks.     Cryer  ^  records  a  case  where  a  supra- 
maxillary  neuralgia  was  traced  to  the  presence  of  a  central  and  lateral 

incisor,  and  a  cuspid  tooth  in  the  anterior  wall 
of  the  antrum ;  they  were  only  discovered  by 
an  exploratory  operation  (Fig.  212).     A  cure 
of  the  neuralgia  was  effected  by  their  removal. 
Impacted  third  molars  frequently  give  rise 
to  heavy  rheumatic  pains  about  the  side  of  the 
face  and  jaws,  and  no  doubt  in  such  cases  as  de- 
picted in  Fig.  199  would  cause  intractable  and  diffuse  maxillary  neur- 
.    Salter  ^  records  a  case  of  long-standing  and  intractable  neuralgia, 
Dental  Cosmos,  1896.  ^  Dental  Pathology. 


algia 


MALPOSITIONS  OF  THE   TEETH.  239 

exhibiting  a  constant  painful  area  upon  the  scalp,  and  in  Avhicli  heat  and 
tenderness  were  noticed  over  a  swelling  upon  the  hard  jmlate.  Imme- 
diate and  permanent  cessation  of  the  neuralgia  followed  removal  of 
the  teeth. 

Symptoms  of  maxillary  periostitis  —  heavy,  gnawing,  and  dull, 
throbbing  pain,  with  more  or  less  heat  and  engorgement  of  tissues — 
are  noted  as  an  accompaniment  of  impacted  teeth.  Such  symptoms 
may  herald  the  appearance  of  the  tip  of  the  tooth  through  its  bony 
covering  and  gum. 

Cases  of  maxillary  abscess,  in  the  absence  of  their  usual  (dental) 
cause,  may  run  a  prolonged  and  painful  course,^  involving  neighboring 
structures,  and  after  free  venting  be  found  to  have  arisen  about  an 
impacted  tooth. 

Occasionally  a  circumscribed  swelling  is  noted  upon  some  aspect  of 
a  jaw,  most  frequently  upon  the  palatal  portion  of  the  superior  maxilla, 
which  is  attended  by  inflammatory  symptoms,  and  an  incision  reveals 
an  impacted  tooth. 

Quickly  forming  cysts  of  the  jaw  upon  receiving  surgical  treatment 
may  be  found  to  contain  the  crown  of  an  entire  tooth,  this  evidently 
being  the  centre  of  irritation  from  w^hich  the  cystic  formation  had  its 
origin. 

Diag-nosis. — The  first  point  of  observance  in  cases  of  suspected 
tooth-encystment  is  an  examination  of  the  dental  arches.  Are  all  of 
the  permanent  teeth  in  position  ?  Given  the  absence  of,  particularly, 
a  lower  third  molar  from  the  dental  arch,  with  a  history  of  no  eruption, 
and  a  persistent  neuralgia,  particularly  if  occasionally  accompanied  or 
alternated  by  heavy  rheumatic,  what  are  known  as  bone-pains,  and  find- 
ing no  other  evident  cause  of  the  neuralgia,  the  effects  of  an  impacted 
tooth  would  be  naturally  diagnosed  as  the  source  of  the  disturbance. 
Impacted  teeth  which  lie  horizontally  or  nearly  so  along  the  palatal 
vault  frequently  cause  a  swelling.  This,  taken  in  conjunction  with  the 
absence  of  a  tooth  from  the  dental  arch,  points  to  a  diagnosis  of  im- 
paction. 

In  very  many  cases  of  impaction  diagnosis  has  been  a  mere  accident, 
discovery  being  made  in  the  course  of  an  exploratory  surgical  operation. 
Modern  science  solves  with  the  .r-ray  the  difficulties  attendant  upon  the 
diagnosis  of  impacted  teeth.  B.  H.  Catching^  was  the  first  to  prac- 
tically apply  this  diagnostic  test  for  the  location  of  an  impacted  tooth. 
The  left  upper  central  incisor  of  a  female  aged  nineteen  became  loos- 
ened, and  an  exploration  through  its  pulp-chamber  revealed  a  hard 
body  occupying  a  position  part  w^ay  up  the  root,  which  had  undergone 

^  See  Garretson'  s  Oral  Surgery,  and  Salter's  Dental  Pathology. 
*  Catching' s  Compend,  1896. 


Fig.  213. 


240       MALFORMATIONS  AND  MALPOSITIONS  OF  THE  TEETH. 

resorption  to  that  point.     The  cuspid  of  the  left  side  was  absent  from 

the  arch.  A  skiagraph  of  the  parts  (Fig.  213)  revealed  the  missing 
cuspid,  whose  crown  had  impinged  upon  and 
caused  resorption  of  the  root  of  the  central 
incisor. 

Impacted  teeth  may  become  uncovered  at 
some  aspect  late  in  life  and  the  condition  be 
discovered  incidentally.  Cases  are  recorded 
where  the  pressure  of  a  plate  has  caused  the 
resorption  of  tissues  overlying  an  impacted  tooth, 
thus  revealing  its  presence.  Fig.  214  illustrates 
a  ease  where  the  presence  of  an  impacted  cusj^id 
was  revealed  at  the  age  of  seventy  years,  through 
resorption  of  the  alveolar  bone  and  the  gum- 
tissue  covering  the  tooth. 
Beyond  a  doubt,  the  »-ray  will  be  generally  used  in  the  future  to 

determine  the  position  of  permanent  teeth  absent  from  the  dental  arch  ; 

and  will  be  used  as  a  means  of  diagnosis  when  the  presence  of  impacted 

teeth  or  an  odontoma  may  be  suspected. 


X-ray  photograph,  showing 
the  malposed  cuspid  en- 
tirely embedded  in  the 
bone,  and  pointing  on  the 
central. 


Fig.  214. 


Treatment. — The  treatment  of  cases  of  impaction  is  the  removal 
of  the  oifending  tooth.  Whether  or  not  this  comes  within  the  prov- 
ince of  the  dental  operator  depends  upon  the  position  of  the  tooth, 
and,  incidentally,  upon  the  usual  range  of  practice  of  that  par- 
ticular practitioner.  When  the  tooth  is  imbedded  deep  in  the  sub- 
stance of  the  jaw,  access  to  it  involves  the  etherization  of  the  patient 
and  the  removal  of  the  bone  which  obstructs  the  path  of  extrac- 
tion ;  this  may  be  an  operation  of  some  magnitude,  and  is  usually  done 
by  a  special  surgical  practitioner.  When,  however,  it  is  evident  that  the 
obstructions  to  the  removal  of  the  tooth  consist  of  the  soft  tissues  and 
but  a  lamina  of  bone,  the  operation  for  removal  is  clearly  within  the 


MALPOSITIONS  OF  THE  TEETH.  241 

province  of  the  dental  operator.  For  example,  the  presence  of  an 
im])acted  ciis})id  is  determined  lying  horizontally  along  the  lateral 
aspect  of  the  roof  of  the  mouth.  The  parts  may  be  injected  with  a 
cocain  or  eucain  solution,  and  a  curved  cut  made  with  a  sharp  bistoury 
through  the  soft  tissues  at  the  dental  side  of  the  swelling  to  the  bone. 
The  flap  thus  outlined  is  raised  from  the  bone,  the  flap  including  the 
periosteum.  A  large  sharp  bur  is  then  employed  to  remove  the  covering 
bone.  When  the  tooth  is  freely  exposed  it  may  be  dislodged  with 
forceps  or  elevator.  The  parts  are  then  washed  with  a  hydrogen  dioxid 
solution,  dried,  the  flap  pressed  back  into  place,  and  steresol  (which  see) 
painted  over  the  parts. 

The  treatment  of  such  cases  as  Fig.  207  is  the  same. 

16 


SECTION  III. 

AFFECTIONS   OF   ENAMEL  AND  DENTIN. 


CHAPTER   XL 
AFFECTIONS  OF  THE  ENAMEL. 

It  has  been  repeatedly  stated  in  the  preceding  pages  that  enamel 
plays  an  entirely  passive  part  in  disease-processes.  Being  cut  off  at  the 
completion  of  its  formation  from  all  sources  of  nutrition,  it  is  deprived 
of  all  defensive  mechanism  against  agencies  which  may  threaten  its 
destruction.  Furthermore,  recognizing  this  absence  of  nutritive  mech- 
anism, it  is  evident  that  enamel  cannot  be  subject  to  the  classes  of  dis- 
eases which  affect  vital  tissues ;  that  is,  degenerations  and  the  causes 
of  degenerations  have  no  representatives  in  affections  of  the  enamel. 
While  the  enamel  may  suffer  loss  of  substance,  it  is  not  possible  that 
constructive  or  retrogressive  metamorphosis  can  take  place. 

The  enamel  can  be  regarded  only  as  an  inert  chemical  substance,  the 
exact  chemical  morphology  and  composition  of  which  are  but  imper- 
fectly understood.  It  is  acted  upon  by  a  variety  of  physical  forces  and 
chemical  agencies  which  threaten  the  destruction  of  its  substance,  either 
through  mechanical  injury  or  chemical  solution,  and  against  which 
agencies  it  is  incapable  of  any  but  mechanical  and  an  unalterable 
chemical  resistance.  The  disease-causes  operating  against  the  integ- 
rity of  the  enamel  of  the  teeth  are  mechanical  and  chemical ;  both 
of  these  cause  a  loss  of  substance,  but  in  a  different  manner ;  again, 
they  may  act  together.  The  mechanical  forces  act  as  destructive  agents, 
either  by  removing  the  enamel  particle  by  particle  by  a  process  of 
abrasion,  or  by  causing  fracture,  complete  or  incomplete,  of  masses  of 
enamel.  It  appears  in  some  cases  that,  in  addition  to  direct  mechanical 
violence,  abnormal  temperatures  to  which  the  enamel  may  be  subjected 
cause  linear  fractures  of  enamel-plates.  Enamel  suffers  from  chemical 
solution  both  through  the  action  of  acids  formed  in  the  mouth  during 
fermentative  processes,  and  probably,  by  morbid  acid  secretions  of 
glands,  also  through  the  action  of  acids  present  in  food  or  taken 
as  medicinal  agents. 

243 


244  AFFECTIONS  OF  THE  ENAMEL. 

Mechanical  Injury  of  Enamel. 

It  was  pointed  out  in  Chapter  VIII.  that  the  resistance  of  enamel 
against  crushing-forces  is  comparatively  slight,  and  that  its  resistance 
in  this  direction  is  much  modified  according  or  not  as  the  tissue  is  uni- 
formly and  firmly  supported  by  dentin.  Masses  of  enamel,  therefore, 
which  are  deprived  of  the  normal  support  of  underlying  dentin  are  in 
danger  of  fracture.  It  is  frequently  noted  that  teeth  which  give  no 
very  apparent  external  indication  of  loss  of  dentin,  the  enamel  contour 
being  almost  intact,  may  exhibit  an  extensive  disorganization  of  the 
dentin,  through  a  comparatively  light  stress  causing  fracture  of  the 
enamel.  Biting  upon  a  crust  may  be  followed  by  crushing  of  the 
greater  portion  of  the  enamel-cap,  revealing,  as  the  underlying  cause 
of  the  fracture,  disappearance  of  dentin  support. 

The  enamel  of  teeth  appears  to  differ  in  fragility,  both  as  regards 
individuals  and  the  several  teeth  of  one  denture.  ^— 

Fracture  of  enamel  en  masse  occurs  more  readily  with  pulpless  teeth, 
those  in  which  decomposition  of  the  contents  of  the  dentinal  tubuli  has 
taken  plabe,  than  it  does  with  teeth  containing  vital  pulps.  Its  resist- 
ance is  much  greater  in  teeth  in  which  the  tooth-pulp  has  been  devital- 
ized and  removed  and  the  canals  filled  under  aseptic  precautions,  with 
absolute  exclusion  of  saliva,  than  when  the  saliva  has  been  permitted 
free  entry  into  the  interiors  of  the  teeth. 

Through  either  lack  of  perfect  adaptation  or  improper  character  of 
support,  enamel-walls  underlaid  by  gold  or  amalgam  fillings  are  much 
more  liable  to  fracture  than  if  supported  by  zinc-phosphate  cement. 
It  should  be  remarked  in  this  connection  that  the  chief  and  most 
valuable  use  of  zinc  phosphate  in  dental  practice  is  as  a  mechanical 
substitute  for  lost  dentin. 

The  accepted  rule  of  operative  dentistry,  not  to  pack  gold  against 
unsupported  enamel-walls,  is  a  well-founded  one.  The  danger  of  frac- 
ture is  twofold  :  first,  fracture  during  the  operation  of  impaction ;  sec- 
ondly, subsequent  fracture  due  to  improper  support. 

Enamel  (see  Chapter  VIII.)  has  lines  of  least  mechanical  resistance, 
which  are  in  planes  at  right  angles  to  the  general  direction  of  the  en- 
amel-rods ;  that  is,  enamel  fractures  most  readily  aU)ng  the  lines  of  the 
cementing-substance  of  the  enamel.  In  addition  to  these  uniform  lines 
of  low  resistance  there  appear  to  be  others  which  invite  fracture  along 
straight  lines  passing  from  the  occlusal  edges  of  the  enamel  to  its  cervi- 
cal border ;  longitudinal  fracture  of  the  entire  length  of  an  enamel  plate 
occurs.  These  lines  may  be  observed  in  the  enamel  of  persons  who 
habitually  break  ice  and  other  hard  substances  with  their  teeth.  Iden- 
tical lines  of  fracture  are  found  in  enamel  which  patients  deny  having 


MECHANICAL  INJURY  OF  ENAMEL.  245 

subjected  to  such  usage ;  they  have  been  attributed  to  the  contact  of 

excessively   hot   or   excessively   cold   substances    with   the  enamel,  a 
reasonable  hypothesis. 


ABRASION    OF   THE    ENAMEL. 

Bv  abrasion  of  the  enamel  is  meant  a  wearing  away  of  its  substance 
through  the  friction  of  mastication  when  gritty  substances  are  present. 
Some  forms  of  abrasion  have  been  attributed  to  the  too  vigorous  use 
of  hard  tooth-brushes,  ])articularly  when  gritty  tooth-powders  are  em- 
ployed. There  is  no  doubt  that  mechanical  abrasion  about  the  necks 
of  teeth  is  produced  in  this  manner,  the  gum-line  receding  beyond  the 
enamel-border,  exposing  the  cementum  :  but  a  careful  examination  will 
reveal  the  cementum,  and  next  the  underlying  dentin  to  be  affected  ;  the 
enamel  is  not  abraded.  These  tooth-brush  abrasions  are  quite  charac- 
teristic (Fig.  215).  In  well-kept  dentures  the  gums  are  seen  to  have 
receded  from  their  normal  line,  but  exhibit  no  evidences  of  turgescence  ; 
the  roots  of  the  teeth,  upper  and  lower,  are  exposed  to  a  greater  or  less 
extent  along  their  labial  and  buccal,  but  not  along  their  lingual  aspects ; 
and  they  are  excavated  to  variable  depths,  upon 
the  bicuspids  and  first  molars  more  than  upon  the  Fig.  215. 

other  teeth,  as  here  the  greatest  force  of  brushing 
is  received.  The  depressions  have  a  normal  den- 
tin color,  which  in  smokers  may  be  periodically 
blackened  by  deposits  of  carbon.  If  caries  super- 
venes, the  abraded  areas  lose  their  normal  color, 
and  may  be  readily  indented  by  sharp  instruments, 
which  they  resist  before  the  advent  of  caries.    The 

bicuspids  and  molars  particularly  may  be  grooved  in  such  manner  as  to 
require  restoration  by  fillings. 

Abrasion    of    enamel-surfiices    through    the    constant   rubbing   of 
metallic  clasps  of  prosthetic  appliances  has  been  said  to  occur,  but  it 
is  impossible  to  disassociate  in  this  connection  the  effects 
of  the  acids  of  fermentation.     Food-debris  on  the  inner  ^^^  ^    • 

surface  of  a  clasp  undergoes  fermentative  changes,  and 
acids  are  formed  which  act  as  decalcifying  agents  upon 
the  enamel ;    so  that  the  abrasion  of  the  clasp  is  not 
upon  normal  enamel-surfoces,  but  upon  partially  decal- 
cified enamel.     This  fact  becomes  more  evident  when  it 
is  observed  that  the  abraded  surfaces  are  not  smooth  and  polished,  but 
are  roughened.     There  is  no  doubt  that  the   continued   rubbing   of  a 
clasp  upon  a  tooth  will  abrade  enamel  slightly,  but  the  surface  produced 
is  polished.     The  abrading  effect  of  clasps  in  contact  with  cementum  or 


246  AFFECTIONS  OF  THE  ENAMEL. 

dentin  is  unquestionable,  but  there  is  also  in  such  cases  the  conjoined 
effect  of  acids  of  fermentation. 

By  far  the  most  common  cause  of  the  abrasions  noted  upon  the 
occlusal  surfaces  of  teeth  is  tobacco-chewing.  The  silex  contained  in 
tobacco-leaf  acts  as  an  irresistible  abrading  agent.  The  cases  in  which 
this  form  of  abrasion  is  most  marked  are  those  in  which  there  has  been 
originally  but  little  overbite  of  the  upper  teeth,  or  in  which  the  teeth 
have  a  tip-to-tip  occlusion.  There  appears  to  be  a  tendency  with  this 
type  of  occlusion  for  the  occlusal  surfaces  of  the  teeth  to  abrade.  There 
are  always  a  free  lateral  movement  of  the  mandible,  and  a  type  of  sur- 
face-contact resembling  that  of  the  herbivora.  Whether  due  to  the 
type  of  occlusion  itself  or  that  with  this  type  of  occlusion  the  individual 
more  frequently  chews  the  siliceous  stems  of  vegetables,  it  is  with  such 
patients  that  general  abrasion  is  most  common.  It  is  also  frequent 
in  those  cases  presenting  the  first  degree  of  prognathism.  In  all  of 
these  cases,  after  the  abrasion  has  worn  down  the  teeth  to  the  cusp- 
bases,  the  occlusion  tends  to  become  of  the  tip-to-tip  variety.  When 
there  is  a  more  marked  overbite  occlusion,  with  a  consequent  lessening 
of  lateral  movement  of  the  mandible,  the  teeth  do  not  acquire  flattened 
contact-surfaces,  but  their  cusps  increase  in  sharpness  and  pointedness. 

The  effects  of  abrasion  are  to  leave  sharp  enamel-edges  standing, 
which  when  the  dentin  becomes  exposed  grow  more  sharp  and  more 
pointed.  Being  without  direct  dentin  support  and  receiving  stress  in 
abnormal  directions,  the  enamel  tends  to  fracture. 

In  the  overbite  cases  the  conjoined  action  of  abrasion  and  of  gradual 
molecular  fracture  of  enamel  creates  curiosities  of  occlusion.  The 
teeth  of  the  upper  and  lower  jaws  may  interlock  their  cusps  in  such  a 
manner  that  the  line  of  junction  is  almost  invisible. 

The  sharp  enamel-edges  produced  not  only  increase  the  liability  to 
enamel-fracture,  but  act  as  constant  sources  of  irritation  to  soft  tissues 
which  come  in  contact  with  them,  the  most  frequent  result  being 
abrasions  upon  the  side  of  the  tongue,  producing  ulcers  of  a  sometimes 
chronic  type  which  acquire  indurated  edges  and  simulate  syphilitic  sores 
or  epithelioma.  The  causal  relationship  between  sharp  edges  of  the 
teeth  and  lingual  epithelioma  appears  to  be  quite  clear  in  some  cases.^ 

Sores  which  have  given  evidence  of  malignancy  and  been  diagnosed 
as  malignant  growths  have  been  cured  by  rounding  and  polishing  sharp 
and  irritating  enamel-edges  of  teeth. 

Treatment  of  Abrasion. — If  seen  early  enough,  the  treatment  of 
abrasion  should  be  preventative.  Abrasion  has  unquestionably  been 
arrested  by  cessation  of  the  tobacco-chewing  habit.  A  difficult  class 
of  cases  to  treat  is  found   in  those   highly  nervous  individuals  who 

^  Garretson's  Oral  Surgery. 


EROSIONS  OF  THE  TEETH.  247 

grit  their  teeth  during  sleep.  It  is  probable  and  reasonable  that  this 
cause  alone  may  serve  to  explain  abrasions  traceable  to  no  other 
source.  The  cure  of  such  cases  as  these  could  only  be  possible 
through  the  wearing  at  night  of  some  modified  form  of  interdental 
splint.  The  cases  naturally  indicate  the  medicinal  use  of  a  l^romid 
before  retiring. 

It  is  rare  that  any  remedial  measures  are  adopted  or,  indeed,  even 
advisable,  unless  the  abrasion  wears  the  teeth  down  far  below  the  cusp- 
line,  although  the  dentin  exposed  through  the  loss  of  enamel  may  become 
hypersensitive  and  require  treatment.  The  mildest  agent  affording 
relief  is  carbolic  acid.  For  the  relief  of  periodical  hypersensitivity 
the  use  of  a  mouth-wash  of  dilute  phenol  sodique  is  effective  if  con- 
tinued. Some  spots  of  hypersensitiveness  resist  every  measure  ex- 
cept applications  of  strong  mineral  acid.  The  action  of  these  acids, 
sulfuric,  nitric,  or  hydrochloric,  being  chemically  destructive,  the  spots 
of  application  must  be  subsequently  excavated  and  filled. 

The  radical  relief  of  the  condition  is  by  the  operation  called  "  shoeing  " 
the  teeth.  Each  abraded  tooth  is  to  have  built  upon  it  sufficient  gold- 
foil  to  receive  the  stress  of  mastication.  The  fillings  must  be  of  such 
thickness  that  the  stress  of  mastication  cannot  alter  their  forms,  and 
be  built  as  solidly  as  molten  gold  ;  to  assure  this  they  are  made  of 
heavy  rolled  foil.  No.  30,  No.  60,  and  for  the  final  surfaces  No.  120. 
In  many  cases  it  is  advisable  to  use  for  this  purpose  platinum-gold  foil, 
which  resists  attrition  better  than  gold-foil  itself. 

Cases  of  attrition  of  the  oral  teeth  and  of  the  bicuspids  are  fre- 
quently seen  where  the  loss  of  several  molar  teeth  has  permitted  the 
entire  stress  of  mastication  to  come  upon  the  anterior  teeth.  These 
cases  are  treated  by  adjusting  bridge  fixtures  in  appropriate  spaces, 
whose  occlusion  shall  raise  the  bite — /.  e.,  separate  the  jaws  to  the 
proper  extent ;  hard-foil  fillings  are  then  inserted  in  the  worn  anterior 
teeth,  restoring  to  them  their  original  forms. 

In  ease  the  abrasion  is  veiw  deep  upon  all  of  the  teeth,  it  is  advisal)le 
to  fit  gold  crowns  of  the  barrel  variety  upon  the  posterior  teeth  and 
adjust  porcelain-faced  crowns  over  the  anterior  teeth.  The  pulps  of 
the  teeth  need  not  necessarily  be  destroyed.^ 

Erosions  of  the  Teeth. 

Erosion  of  the  teeth  is  a  term  applied  to  the  decalcification  of  the 
hard  tissues  of  teeth  in  such  a  manner  that  broad,  shallow  excavations 
are  made  in  the  enamel,  and  in  such  situations  that  the  acids  of  fermen- 
tation and  mechanical  abrasion  are  clearly  excluded  as  exciting  causes. 
The  excavations  occur  upon  surfiices  Avhere  fermentative  processes  are 
^  See  Avierican  Text-book  of  Prosthetic  Dentistry,  chapter  sxii. 


248 


AFFECTIONS  OF  THE  ENAMEL. 


in  least  degree  and  where  attrition  is  nil.     Figs.  217,  218,  and  219 
illustrate  the  characteristic  appearance  of  areas  of  erosion. 

The  labial  faces  of  the  anterior  teeth  are  more  frequently  aifected  than 
those  of  any  of  the  other  teeth.    These  surfaces  appear  as  though  sections 


Fig.  217. 


Fig.  218. 


(Darby.j 


(Darby.) 


had  been  bodily  cut  out  of  them.     The  enamel  is  affected  to  a  greater 
extent  than  the  dentin,  forming  shallow  excavations  in  the  teeth.    When 


Fig.  219. 


A  ease  of  erosion  (drawn  from  the  cast) :  B,  silhoutte  from  a  perpendicular  line  through  the  left 
centrals,  upper  and  lower,  showing  the  loss  of  substance.    (Black.) 

the  destructive  action  lays  bare  the  dentin,  neither  it  nor  the  enamel 
presents  any  of  the  appearances  of  dental  caries,  the  eroded  surfaces 
being  smooth  and  polished  and  of  normal  hardness. 


CAUSES. 

From  the  chemical  composition  of  the  enamel  it  is  at  once  evident 
that  the  essential  cause  of  the  loss  of  structure  must  be  an  acid ; 
only  acid  substances  can  dissolve  it.  The  question  of  mechanical 
abrasion  may  be  set  aside  because  erosion  has  been  found  upon  the  teeth 
of  individuals  who  had  never  used  a  tooth-brush,  and  the  situation  of  the 
areas  precluded  the  idea  of  abrasion  by  mastication.  It  is  evident  that 
the  acid  must  be  of  localized  formation,  because  if  of  general  distri- 
bution the  lingual  and  occlusal  faces  of  the  teeth  would  be  affected 


EROSIONS  OF  THE  TEETH.  249 

equally  with  the  labial.  It  will  be  observed  that  the  areas  of  erosion 
are  in  situations  in  which  food-debris,  fermentable  material,  collects  in 
least  amount,  and  where  the  acids  of  fermentation  necessarily  form  in 
slight  amount.  This  survey  materially  narrows  the  field  of  inquiry. 
What  structures  or  substances  can  form  acids  or  acid  bodies  about  the 
labial  faces  of  the  teeth,  excluding  fermentative  processes?  The 
inquirer  is  of  necessity  driven  to  the  belief  that  local  acid  secretion  is 
the  active  cause.  Secretion  implies  the  existence  of  glandular  tissue, 
and  the  only  glands  in  close  relationship  with  the  labial  faces  of  the 
teeth  are  the  muciparous  glands  of  the  lips  ;  mucus-forming  glands, 
called  labial  follicles.  Edward  C.  Kirk  ^  first  pointed  out  the  prob- 
ability of  altered  (acid)  secretion  of  these  glands  being  the  active  cause 
in  the  production  of  erosion. 

It  has  been  recorded  by  those  who  have  made  a  special  study  of  the 
condition  that  females  are  more  frequently  affected  than  males  ;  that  it 
rarely  becomes  evident  before  the  age  of  thirty  or  later ;  and,  finally, 
that  patients  in  whom  it  is  noted  are  usually  the  victims  of  the  condition 
indefinitely  known  as  the  gouty  diathesis.  The  observations  of  Kirk, 
Darby,  Jack,  and  myself  have  all  had  a  singular  unanimity  of  agree- 
ment in  this  direction.  ^lost  of  the  patients  give  a  family  history  of 
gout,  and  very  commonly  a  personal  or  contemporary  family  history  of 
rheumatoid  arthritis  or  rheumatism.  Even  when  the  existence  of  rheu- 
matoid or  gouty  affections  is  denied  by  both  patient  and  medical  attend- 
ant, it  is  rare  that  the  patient  does  not  complain  of  some  general  disorder, 
the  usual  ones  being  neuralgia  of  long  standing,  marked  anaemia,  or 
perhaps  neurasthenia.  Be  the  condition  what  it  may,  the  essential 
disease-process  is  one  which  may  be  traced  to  the  effects  of  suboxidation 
in  the  tissues. 

The  researches  of  general  pathologists  as  to  the  products  of  cell- 
oxidation  but  insufficiently  explain  the  origin  and  significance,  both 
chemical  and  pathological,  of  a  series  of  bodies  related  to  urea,  un- 
questionably waste-products  resulting  from  broken-down,  oxidized  albu- 
minous matter.  These  related  products  are  uric  acid,  xanthin,  and  hypo- 
xanthin,  which  represent,  chemically  at  least,  degrees  of  albuminous 
oxidation — urea  the  most  oxidized,  hypoxanthin  the  least.  While  the 
writer  is  aware  ^  that  pathological  chemists  refuse  to  recognize  uric  acid 
as  a  midway  product  in  urea-formation,  yet  it  cannot  be  denied  that 
uric  acid  will  form  in  increased  amount  if  the  oxidizing  function  be 
below  par  ;  all  clinical  and  scientific  reasoning  appears  to  point  to  this 
end.     Xote  the  conditions  in  which  an  increase  of  uric-acid  formation  is 

1  Dental  Coxmos,  1886. 

*  See  Levison  on  Uric  Acid ;  Luff,  Croonian  Lectures,  1897  ;  Halliburton,  Chcm. 
Physiol,  and  Pathology. 


250  AFFECTIONS  OF  THE  ENAMEL. 

observed.  It  should  be  remarked  parenthetically  that  uric  acid  cannot 
exist  free  as  uric  acid  in  the  blood,  but  when  formed  combines  imme- 
diately with  sodium  or  magnesium,  doubtless  displacing  the  negative 
radical  of  compounds,  and  forming  sodium  or  magnesium  quad-urates. 

An  excess  of  urates  is  formed  whenever  there  is  an  excess  of  white 
blood-corpuscles,  in  conditions  of  anaemia,  leukaemia,  and  so  on.  The 
significance  of  these  conditions  lies  more  in  the  deficiency  of  red  cor- 
puscles than  in  the  excess  of  white.  Less  red  corpuscles,  less  haemo- 
globin, less  oxygen  carried,  hence  diminished  oxidation  in  the  cells. 
Again,  in  the  opposite,  the  plethoric  individual,  who  suffers  from  acute 
outbreaks  of  gout,  large  quantities  of  albuminous  food  are  taken, 
amounts  far  in  excess  of  that  required  to  replace  waste ;  frequently, 
owing  to  glandular  disturbances  of  the  alimentary  canal,  the  material  is 
insufficiently  elaborated,  and  the  tissues  of  the  body  are  drenched  with  an 
excess  of  material  in  unfit  chemical  state  for  cell-metabolism  ;  the 
amount  of  oxygen,  actually  large,  relatively  small,  is  insufficient  to 
oxidize  all  of  the  material  of  which  the  cells  of  the  body  should  rid 
themselves.  Conjoined  with  this,  the  same  individuals  usually  consume 
too  much  alcohol  in  one  form  or  another,  and  alcohol  notably  lessens 
cell-oxidation. 

The  relation  between  an  excessive  formation  of  urates  and  deficient 
oxidation  may  in  a  like  manner  be  made  out  in  many  of  the  other  con- 
ditions. A  deficiency  of  oxidation  or  in  the  supply  of  oxygen  is,  of 
course,  accompanied  by  retention  of  COg  in  cells,  so  that  all  of  the 
waste-products  of  cells  are  but  imperfectly  removed.  It  should  also  be 
noted  that  the  products  of  cell- waste  are  acid  in  reaction. 

"  If  the  orbicularis  oris  muscles  be  dissected  from  the  mucous  mem- 
brane of  the  lip,  the  labial  glands  may  be  observed ;  they  are  more 
numerous  near  the  centre  than  at  the  extremities  of  the  lip"  ^ — i.  e.,  the 
greater  number  overlie  the  labial  faces  of  the  incisors  toward  the 
necks  of  these  teeth.  "  These  are  small  racemose  glands,  their  ducts 
lined  with  low  granular  epithelium ;  in  the  alveoli  the  cells  are  larger 
and  columnar  and  stain  less  readily  with  carmine."  "  Their  secretion  is 
composed  of  water,  mucin,  and  inorganic  salts,  sodium  phosphate  pre- 
dominating, which  gives  the  fluid  its  alkalinity  under  normal  condi- 
tions. In  conditions  of  irritation  and  consequent  hypersemia  the 
secretion  becomes  increased  in  amount  and  acid  in  reaction  (Kirk).  The 
nature  of  the  acid  is  not  clearly  known.  Brubaker^  suggested  that  it 
might  arise  as  follows  : 

In  the  condition  known  as  the  gouty  diathesis  there  are  evidences 
of  widespread  irritation ;  the  presence  of  an  excess  of  waste-products 
appears  to  be  the  cause  of  the  irritation.  In  consequence  of  the  irrita- 
^  Brubaker,  International  Dental  Journal,  Dec,  1894.  ^  Ibid. 


EROSIOXS  OF  THE  TEETH.  251 

tion  there  is  a  vascular  reaction  about  glands,  as  those  under  con- 
sideration, which  results  in  increased  secretion,  and  as  the  oxidizing 
function  is  imperfect  the  CO2  accumulates.  "  Given  upon  one  side, 
the  vascular  side,  of  the  cells  the  readily  diffusible  and  alkaline  salt 
sodium  phosphate,  Xa^HPO^,  and  in  the  cell  an  excess  of  COj,  existing 
as  H0CO3,  or  carbonic  acid,  when  the  sodium  salt  diffuses  into  the  cell 
the  following  reaction  occurs  : 

Na^HPO,  +  H,C03  =  XaH,PO,  +  NaHCOg/ 

That  is,  dihydrogen  sodium  phosphate  (acid  sodium  phosphate)  and 
acid  sodium  carbonate  are  formed.  Dihydrogen  sodium  phosphate, 
being  acid  in  reaction,  is  capable  of  effecting  the  decomposition  of 
the  calcium  phosphate  of  the  teeth  after  the  following  manner : 

XaH^PO,  +  Ca3(PO,),  =  NaCaPO,  +  2HCaPO,. 

"  The  acid  sodium  phosphate  formed  in  the  gland-cells  and  given  off 
by  them  attacks  the  calciimi  salts  of  the  enamel,  as  above  expressed,  a 
double  decomposition  occurring,  sodium  calcium  phosphate  and  acid 
calcium  phosphate  being  formed.  The  latter,  acted  upon  by  additional 
molecules  of  the  dihydrogen  sodium  phosphate, 

XaH,PO,  +  2CaHPO,  =  XaCaPO,  +  Ca(H,PO,)2 

and  the  freely  soluble  diacid  calcic  phosphate  is  formed.  In  this  way 
the  calcium  phosphate  of  the  teeth  undergoes  decomposition  into,  first, 
mono,  and,  second,  the  diacid  calcic  phosphate."  Brubaker  immersed 
a  tooth  for  a  week  in  a  solution  of  acid  sodium  phosphate,  subjecting 
it  daily  to  tooth-brush  friction,  and  at  the  end  of  that  time  spots  and 
grooves  resembling  areas  of  erosion  made  their  appearance. 

AVhile  admitting  the  probability  that  dihydrogen  sodium  j)hosphate 
is  the  decalcifving  agent,  Kirk  maintains  -  that  the  reaction  between 
the  hypothetical  substance,  carbonic  acid,  H.COo,  and  sodium  phosphate 
is  a  chemical  im]')0ssibility,  as  the  reaction  given  involves  the  production 
of  acid  sodium  carbonate  in  the  presence  of  acid  sodium  phosphate, 
which  cannot  occur. 

He  suggests  that  the  probable  origin  of  the  acid  sodium  salt  is  from 
the  reaction  occurring  between  hydrogen  disodium  phosphate,  Na^HPO^, 
and  uric  acid,  C^H^N^Og,  citing  from  Hammersten  that  uric  acid,  soluble 
in  a  warm  solution  of  hydrogen  disodium  phosphate,  HXaoPO^,  in  an 

'  It  is  to  be  understood  that  Brubaker  advances  this  explanation  hypothetically,  not 
as  an  assured  demonstration,  as  he  says  there  are  no  present  tests  by  which  such  small 
amounts  of  the  acid  substance  can  be  detected. 

^  Private  communication. 


252  AFFECTIONS  OF  THE  ENAMEL. 

excess  of  the  acid,  a  double  decomposition  or  atomic  interchange  occurs 
as  follows  : 

HNa^PO,  +  CsH.N.Og  =  H^NaPO,  +  C^HgNANa, 

resulting  in  the  formation  of  sodium  biurate  and  the  acid  sodium  phos- 
phate, HgNaPO^,  which  may  act  as  a  decalcifying  agent  after  the  manner 
described  by  Brubaker. 

The  uric  acid  involved  in  the  reaction  is  to  be  regarded  as  a  conse- 
quence of  faulty  oxidation  in  the  glandular  tissues.  The  sodium  biurate 
found  in  the  reaction  given  above  may  act  as  an  irritant  and  induce  a 
continuation  of  the  glandular  affection. 

Kirk  has  pointed  out  that  the  contents  of  the  labial  glands  in  cases 
of  erosion  gave  an  acid  reaction — i.  e.,  reddened  blue  litmus  paper — in 
all  of  the  cases  tested  by  him. 

It  appears  to  be  almost  self-evident  that  there  must  be  some  modifying 
factor  causing  the  peculiar  forms  of  the  eroded  areas,  and  that 
it  must  be  an  abrasive.  In  many  of  the  cases  where  the  ero- 
sions are  in  the  form  of  transverse  grooves  or  pits  there  is  no 
doubt  that  the  action  of  the  tooth-brush  upon  the  decalcified  parts 
removes  the  latter ;  the  areas  of  erosion  may  be  oval,  circular, 
or  irregular  patches ;  again,  decalcification  may  appear  to  occur 
over  the  entire  labial  surfaces  of  teeth  uniformly ;  moreover,  as 
stated,  erosions  in  grooves  may  occur  upon  the  teeth  of  persons  who 
do  not  use  a  tooth-brush.  It  is  evident  then  that  in  these  cases  the 
mechanical  factor  must  be  sought  in  the  muscular  movements  of  the 
lips  and  tongue.  The  greatest  effect  of  lip-movement  would  be  upon 
the  entire  labial  faces  of  the  central  incisors,  as  the  maximum  force  of 
contact  of  lips  with  teeth  is  at  and  near  the  median  line,  when  the  lips 
are  alternately  raised  and  depressed.  The  action  of  the  tongue  upon 
the  labial  faces  of  the  teeth  would  be  in  a  curved  line  passing  across 
the  labial  and  buccal  surfaces  of  the  teeth,  beginning  at  the  occluso- 
buccal  portions  of  the  first  molars,  and  having  its  highest  point  at  the 
necks  of  the  central  incisors. 

In  the  light  of  present  knowledge,  odd  and  isolated  situations  of 
areas  of  erosion  can  only  be  referred  to  localized  gland  affections ;  the 
glands  overlying  the  spots  of  erosion  being  alone  affected. 

MORBID    ANATOMY. 

It  is  evident  that  we  have  to  do  with  a  chemical  solution  of  calcium 
salts  as  the  only  distinctive  feature  of  this  disorder ;  the  progress  of  the 
affection  is  essentially  different  from  that  of  dental  caries,  in  which 
chemical  solution  is  but  one  fea*ture.  It  is  difficult  to  reconcile  two 
apparently  contradictory  conditions  in  connection  with  erosion.     It  is 


EROSIONS  OF  THE  TEETH. 


253 


believed  that  only  an  acid  snbstance  can  cause  the  decalcification,  the 
molecular  destruction  of  the  enamel  and  dentin,  and  yet  it  is  recognized 
that  the  application  of  an  acid  produces  roughening  of  the  tooth-sur- 
faces ;  in  erosion  the  surfaces  are  frequently  highly  polished. 

Fig.  220.  Miller '  states  that  "  eroded  teeth  preserve 

their  polish  upon  calcining,  which  shows  that 
the  polish  pertains  to  the  inorganic  constitu- 
ents of  dentin." 

The  general  progress  of  the  decalcification 
is  as  shown  in  Fig.  220.  The  enamel  is  first 
cupped  out,  usually  in  a  transverse  groove, 
which  maintains  its  general  form,  increasing 
in  depth  and  width  until  the  dentin  is  ex- 
posed ;    if  the  carious  process  be  not  grafted 

Fig. 221. 


General  direction  of  stria?  of  Retzius. 


Cases  of  erosion  of  the  lower 
anterior  teeth  (drawn  from 
a  cast  prepared  by  E.  D. 
Swain,  of  Chicago) :  B,  sil- 
houettes representing  the 
loss  of  substance  in  five  of 
the  affected  teeth :  1,  right 
lateral  incisor ;  2,  right  cen- 
tral; 3,  left  central;  4,  left 
lateral;  5,  left  cuspid.  The 
lines  a,  a,  a,  a,  a  show  the  po- 
sition of  the  margin  of  the 
gum.  A  line  is  drawn  also 
to  show  the  original  form 
of  the  tooth.    (Black.) 


upon  erosion,  the  excavation  does  not  mate- 
rially alter  in  form.  The  dentin  when  exposed 
is  usually  firm  and  polished,  and  in  many  cases 
assumes  a  translucent  appearance,  indicative  of 
structural  changes. 

The  shape  of  the  excavation  in  the  enamel 
appears  to  bear  a  somewhat  close  relationship 
with  the  striae  of  Retzius.  These  striae  (see 
Chapter  VII.)  are  lines  in  the  enamel  which 
appear  to  represent  an  orderly,  regular,  and 
periodical  deposit  of  pigment  in  the  forming  tissue,  and  their  distribu- 
tion is  of  such  character  as  to  mark  the  size  of  the  enamel-cap  at  different 
periods  of  its  formation  (Fig.  221).  The  presence  of  the  pigmentary 
material,  whatever  it  may  be,  leads  to  the  inference  that  these  lines  in 
the  enamel  differ  in  some  degree  in  chemical  composition  from  the  other 
portions  of  the  tissue ;  there  is  possibly,  or  probably,  some  degree  of 
difference  in  the  comparative  solubilities  of  the  pigmented  and  non- 
1  Dental  Cosmos,  1894,  p.  269. 


254  AFFECTIONS  OF  THE  ENAMEL. 

pigmented  enamel.  Color  is  lent  this  view  if  a  careful  examination  be 
made  of  the  form  of  the  excavation  in  the  early  stages  of  a  typical 
case  .of  erosion.  The  base  of  the  eroded  cavity  appears  to  lie  upon  suc- 
cessive striae  of  the  enamel.  The  decalcification  appears  to  proceed 
inward  until  one  of  these  striae  is  met,  which,  furnishing,  an  increased 
chemical  resistance  to  the  action  of  the  decalcifying  agent,  causes  the 
process  of  decalcification  to  proceed  more  rapidly  along  the  lines  between, 
the  striae.  Williams  ^  has  shown  that  the  decalcification  of  enamel  in 
caries  finds  lines  of  greatest  chemical  resistance  in  lines  of  enamel-strati- 
fication. It  is  possible  that  some  of  these  lines  irregularly  situated  may 
govern  the  direction  which  the  erosive  process  may  take ;  but  characteris- 
tically they  appear  first  to  be  checked  and  directed  by  the  striae. 

SYMPTOMS   AND   DIAGNOSIS   OF    EROSION. 

So  far  as  the  enamel  is  concerned,  erosion  can,  of  course,  present  no 
symptoms  ;  it  can  only  exhibit  signs,  which  are  the  excavations  them- 
selves, their  forms,  and  the  characters  of  their  walls.  When  the  dentin 
becomes  exposed  an  annoying  hypersensitivity  is  occasionally  observed. 
An  examination  of  the  lip  will  usually  reveal  the  labial  follicles  to  be 
enlarged  ;  and  if  the  mucous  membrane  be  dried,  a  strip  of  blue  litmus 
paper  laid  over  it,  and  the  lip  pressed,  the  contents  of  the  follicles 
will  be  forced  out.  "  If  the  test  be  made  in  the  morning,  before  break- 
fast, the  litmus  will  be  reddened.  This  acid  reaction  is  not  marked 
during  the  day."^ 

The  existence  of  erosion  has  become  a  valuable  diagnostic  sign  for 
the  general  practitioner  in  his  search  for  the  nature  of  masked  mala- 
dies from  which  patients  frequently  suffer.  Obscure  gout  has  been 
pointed  out  through  dental  indications  alone,  where  the  practitioner 
had  before  been  baffled  in  his  diagnosis. 

TREATMENT    OF    EROSION. 

The  treatment  of  erosion  divides  itself  under  two  heads :  prophy- 
lactic and  restorative ;  the  prophylactic  is  again  divided  into  local  and 
general  treatment.  The  problem  of  eradicating  the  cause  of  the  dis- 
order lies  in  a  correction  of  the  morbid  glandular  secretion.  It  is 
evident  that  if  the  irritation  and  altered  secretion  of  these  glands  be 
due  to  some  systemic  cause,  a  disease  of  suboxidation,  notably  an  affec- 
tion of  the  gout  order,  a  cure  of  the  local  disturbance  involves  the 
cure  of  the  underlying  systemic  cause. 

The  eifect  of  an  anti-gout  regimen  and  anti-gout  therapeusis  upon 
the  advance  of  the  erosion  has  not  been  sufficiently  tested  or  observed 
to  furnish  reliable  data  in  this  connection  ;  but  so  far  as  tests  have  gone 
^  Dental  Cosmos,  1897.  ^  Truman. 


ENA3IEL-STAINS.  255 

such  treatment  appears  to  lessen  the  formation  of  acid  substances  by 
the  hibial  glands.  Brubaker  (supra)  has  suggested  tlie  advisability  of 
destroying  these  glands  by  means  of  the  electrocautery,  as  a  radical 
cure  of  the  progress  of  erosion. 

Next  in  importance  to  the  prevention  of  acid  formation,  is  its 
neutralization.  This  implies  the  application  of  alkalies  or  the  use  of 
alkaline  mouth-washes.  The  greatest  production  of  acid  occurring 
during  the  night,  applications  of  adhesive  masses  of  alkaline  substances 
are  made  to  the  teeth  at  night.  The  principal  of  these  is  prepared 
chalk,  calcium  carbonate ;  it  is  rubbed  over  the  labial  faces  of  the  teeth 
and  between  them,  before  retiring.  It  remains  in  sufficient  amount  to 
neutralize  any  acid  substances  coming  in  contact  with  it. 

Excellent  results  as  to  the  checking  of  the  progress  of  the  decal- 
cification are  obtained  from  the  use  of  magnesium  hydrate  ^ — pre- 
cipitated magnesium  hydrate  held  in  suspension  in  water,  milk  of 
magnesia.  Kirk  found  that  three  hours  after  the  use  of  a  teaspoonful 
of  the  milk  of  magnesia  that  the  saliva  maintained  an  alkaline  reaction. 
It  is  deposited  in  a  film  over  the  surfaces  of  the  teeth,  making  an 
alkaline  coating.  It  should  be  used  freely  before  retiring  at  night. 
If  the  patient  care  to  take  sufficient  trouble,  it  is  an  excellent  practice 
to  dry  the  labial  faces  of  the  teeth  each  evening  and  paint  them  with  a 
solution  of  amber  in  chloroform. 

Restorative  Treatment. — If  the  cavities  of  erosion  are  treated  as 
cavities  of  decay,  excavated  and  filled,  it  is  found  that  the  erosive 
process  goes  on  around  the  edges  of  the  fillings,  leaving  the  latter 
projecting  as  metallic  islands  from  the  surfaces  of  the  teeth.  Many 
operators,  deeming  the  insertion  of  gold  fillings  unwarrantable  under 
the  conditions,  advocate  and  insert  zinc-phospate  fillings,  replacing 
them  as  often  as  necessary.  The  filling-material  itself  undergoes  a 
decomposition  similar  to  that  of  the  enamel,  so  that  it  becomes  cupped 
out.  Such  fillings  should  be  well  polished  and  varnished.  If  the  cavi- 
ties are  of  proper  form,  porcelain  or  glass  inlays^  may  be  used  with 
advantage.  Like  other  fillings,  they  must  be  renewed  when  necessary. 
About  the  necks  of  the  lower  teeth  the  restorations  are  usually  made 
with  amalgam. 

Enamel-stains. 

Stains  of  the  enamel  are  not  to  be  confounded  with  deposits  of  deeply 
colored  calculi,  although  there  is  no  doubt  some  similarity  in  the  chemi- 
cal conditions  which  bring  about  the  discoloration  in  both  instances. 
The  nature  and  differences  between  these  pigmentary  deposits  were  first 
set  forth  by  Miller,'^  but  the  questions  involved  are  still  sub  judice. 

^  Kirk,  Dental  Cosmos,  1893.  '  See  American  Text-book  of  Operative  Dentistry. 

3  Denial  Cosmos,  1894. 


256  AFFECTIONS  OF  THE  ENAMEL. 

METALLIC   STAINS. 

Copper. — Miller  found  that  "  workers  in  copper,  brass,  or  bronze 
all  presented  a  green  stain  upon  the  upper  teeth,  showing  every  shade 
of  green  and  bluish-green  up  to  bluish-purple.  The  latter  color  pre- 
dominated in  rooms  where  phosphor-bronze  was  worked."  Attention  is 
called  to  the  fact  that  "  trumpeters  very  often  show  a  discoloration  of 
the  teeth."  Similar  discolorations  are  sometimes  noted  in  proximity  to 
copper-amalgam  fillings.  The  presence  of  copper  was  demonstrated 
in  scrapings  from  some  of  the  stained  teeth,  imparting  a  characteristic 
green  color  to  a  Bunsen  flame. 

Iron. — "  Workers  in  iron  presented  stains  of  a  brownish  color."  As 
pointed  out,  "  the  green  salts  of  iron  under  the  conditions  found  in  the 
mouth  would  become  oxidized  and  brownish  in  color."  The  administra- 
tion of  iron  salts  medicinally  is  believed  to  produce  black  discolorations, 
iron  sulfid  being  formed.  "  Iron  deposits  are  usual  in  the  border-line 
between  carious  and  normal  dentin."  It  is  usually  believed  that  the 
brownish  spots  frequently  seen  in  connection  with  incipient  or  arrested 
caries  of  the  underlying  enamel  are  due  to  the  formation  of  iron  salts. 

Manganese. — Manganese  was  found  in  the  dark-colored  deposits 
upon  the  teeth  of  herbivorous  animals,  but  as  yet  not  upon  those  of 
man.  The  investigators  state  "  that  alkaline  saliva  may  be  necessary  to 
the  production  of  these  deposits." 

Mercury. — In  cases  of  prolonged  mercurial  administration  the 
deposits  (black)  upon  the  teeth  may  give  the  reaction  for  mercury.  "  If 
mercury  and  potassium  iodid  are  given  together,  the  green  iodid  of  mer- 
cury might  be  present  upon  the  teeth."  It  is  probable  in  these  cases 
that  another  discolorfng  substance  may  form.  There  is  in  mercurialism 
more  or  less  gingivitis ;  the  gums  are  swollen  and  spongy,  bleeding 
readily.  "  More  or  less  putrefactive  decomposition  of  the  albuminous 
matter  present  upon  the  teeth  occurs,  and  hydrogen  sulfid  is  formed. 
Reacting  upon  the  oxyhsemoglobin  of  the  blood,  sulfo-methsemoglobin 
is  formed — greenish-red  in  concentrated,  green  in  dilute  solutions." 
Miller  ascribes  the  discoloration  found  in  conditions  of  gingivitis  from 
various  causes,  with  lack  of  hygienic  care,  to  a  probable  reaction  between 
hydrogen  sulfid  and  oxyhsemoglobin. 

Lead. — Hirt  (quoted  by  Miller)  found  in  cases  of  lead-poisoning  dis- 
colorations upon  the  teeth  :  dark  brown  at  the  necks,  light  brown  on 
the  crowns,  with  sometimes  a  trace  of  yellowish-green.  Miller's  tests 
(limited  in  number)  showed  no  lead  reaction  from  the  dental  deposits  in 
lead-poisoning. 

Nickel. — Some  of  the  salts  of  nickel  are  green.  "  Metallic  nickel 
attacked  by  fluids  of  the  mouth  and  mixtures  of  bread  and  saliva  pro- 


ENAMEL-STAINS. 


257 


duce  greenish  salts.     The  writer  has  seen  the  entire  root  of  a  tooth  ^  con- 
taining a  nickel  rctaining-screw  stained  a  uniform  apple-green." 

Silver. — The  dentin  of  pulpless  teeth  containing  amalgam  fillings  is 
sometimes  stained  black,  owing  to  the  formation  of  silver  sulfid,  but 
as  yet  no  silver  deposits  upon  enamel  have  been  detected. 


GREEN    STAIN. 


This  most  common  of  green  deposits  upon  enamel  occurs  upon  both 
the  temporary  and  the  permanent  teeth  of  young  persons.  The  de])Osits 
usually  have  a  crescentic  form,  are  mainly  upon  the  labial  faces  of  the 
anterior  teeth,  and  may  be  but  a  narrow  line  or  may  cover  one-half  the 
labial  face.  It  is  unusual  for  the  deposits  to  extend  far  into  the  inter- 
proximal spaces,  their  tendency  being  to  follow  the  edges  of  the  proxi- 
mal surfaces.  While  green  stain  undoubtedly  does  form  upon  adult 
teeth  (Figs.  222  and  223)  where  clearly  the  enamel-cuticle  has  long  been 


Fig.  222. 


Fig.  223. 


Extension  of  green  stain  on  the  approximal  sur-       Extension  of  green  stain  on  the  lingual  surface 
face  of  the  incisors.    (Miller.)  of  incisors.    (Miller.) 

absent,  it  is  only  very  common  upon  young  teeth  where  remnants  of 
Nasmyth's  membrane  persist  about  their  necks.  The  color  of  these 
deposits  varies  from  light  green  to  greenish-black. 

If  an  instrument  be  passed  over  the  portion  of  enamel  affected, 
more  or  less  roughness  of  the  surface  is  evident.  If  the  deposits  are 
subjected  to  friction  with  abrasives,  they  disappear  slowly  and  the 
enamel  beneath  is  found  roughened.  This  has  led  to  the  belief  that  these 
deposits  cause  decalcification  of  the  enamel.  It  is  found  upon  adult 
teeth  that  when  an  area  of  cervico-labial  enamel  has  become  roughened 
through  slight  decalcification,  that  green  stain  is  likely  to  form  upon 
the  rough  surface,  if  proper  hygienic  care  be  not  exercised.  It  is 
also  found  that  if  the  stain  be  removed  by  means  of  abrasives,  the 
roughened  enamel  may  be  readily  polished — /.  e.,  the  decalcification  is 
very  superficial. 

If  cases  be  observed  early  enough  in  childhood,  it  will  be  noted  that 
green  stain  is  usually  preceded  by  a  lack  of  oral  hygiene ;  collections 
^  Specimen  in  possession  of  E.  C.  Kirk. 
17 


258  AFFECTIONS  OF  THE  ENAMEL. 

of  food-debris  are  not  removed  from  about  the  necks  of  the  teeth, 
which  implies  that  prior  to  the  formation  of  green  stain  the  affected 
enamel-surfaces  have  been  subjected  to  the  action  of  fermenting  food- 
debris — that  is,  to  acids.  These  facts  have  led  to  a  general  acceptance 
of  the  view  that  the  roughness  or  decalcification  has  preceded  the  green 
deposits.  "  If  teeth  be  placed  in  a  10  per  cent,  solution  of  hydrochloric 
acid,  in  from  two  to  four  minutes  the  enamel-cuticle  begins  to  loosen, 
and  in  from  five  to  ten  minutes  is  isolated.  It  is  found  that  the  entire 
stain  comes  away  with  the  cuticle."  ^ 

Nature  of  Coloring'-inatter. — The  coloring-matter  is  found  to  be 
insoluble  in  water,  glycerin,  alcohol,  ether,  chloroform,  and  oil  of  tur- 
pentine. Mineral  acids,  hydrochloric,  nitric  and  nitro-hydrochloric,  act 
but  slowly  upon  the  coloring-matter ;  even  hydrochloric  acid  requires 
some  hours  to  completely  destroy  it.  Tincture  of  iodin,  commonly  be- 
lieved to  act  as  a  solvent  of  green  stain,  was  found  to  affect  it  but 
slightly.  Both  chlorin  and  nascent  oxygen  destroy  the  coloring-matter 
rapidly,  the  cuticles  being  bleached  in  a  few  minutes  by  a  10  per  cent. 
solution  of  hydrogen  dioxid.  Thick,  dark-green  deposits  were  incom- 
pletely bleached  after  eight  hours'  immersion  in  the  10  per  cent.  HjOg 
solution,  pointing  to  a  lack  of  uniformity  in  the  comjDosition  of  the 
stain. 

The  belief  that  the  green  coloring-matter  is  chlorophyll  is  contra- 
dicted by  the  fact  that  it  is  not  soluble  in  ether. 

So  far  as  present  evidence  is  possessed,  the  association  of  the  green 
discoloration  with  sulfo-methsemoglobin,  or  some  allied  substance,  is 
the  most  probable  explanation. 

Furthermore,  there  is  no  evidence  that  green  deposits  stand 
in  causative  relation  to  enamel  decalcification ;  as  pointed  out, 
they  are  more  probably  deposits,  following  upon  limited  decalci- 
fication. 

Treatment  of  Enamel-stains. — The  general  modes  of  treating  stain- 
ing of  the  dentin  -  are  not  of  general  application  in  the  treatment  of 
enamel-stains.  The  problem  in  the  removal  of  metallic  stains  is  to 
transform  an  insoluble  metallic  salt  into  a  soluble  one.  The  most  fre- 
quent and  most  practicable  course  in  dealing  with  metallic  stains  of  the 
dentin  is  to  form  soluble  chlorids  through  the  action  of  nascent  chlorin. 
Copper,  nickel,  and  iron  stains  should  be  treated  hx  repeated  and  con- 
tinued washings  with  chlorin-water  ;  silver  the  same,  or  be  acted  upon 
by  iodin  tincture,  forming  soluble  iodid,  and  so  on  ;  but  as  all  of  these 
deposits,  including  green  stain,  are  very  superficial,  the  rational  course 
of  treatment  is  their  mechanical  removal  by  means  of  abrasives.  A 
mixture  of  powdered  pumice-stone  and  glycerin  is  used  in  conjunction 

^  Miller,  Ibid.  ^  American  Text-book  of  Operative  Dentistry. 


ENAMEL  SOLUTION.  259 

with  rapidly  revolving;  leather  wheels,  brushes,  and  rubber  cups,  until 
every  vestige  of  the  deposit  has  disappeared  and  the  enamel  surface  is 
polished. 

Enamel  Solution. 

Usually  the  first  stage  of  dental  caries  consists  of  a  solution  of  the 
calcium  basis  of  the  enamel ;  the  decalcification  is  a  distinctive  phase 
of  dental  caries,  and  will  be  discussed  under  that  head. 


CHAPTER   XII. 
DISEASES  OF  THE  DENTIN. 

The  dentin,  as  shown  in  Chapters  VII.  and  VIII.,  is  made  up  of  a 
matrix  of  calcified  tissue  traversed  by  innumerable  filaments  or  pro- 
cesses, which  are  vital  protoplasmic  prolongations  of  the  peripheral 
cells  of  the  pulp.  The  matrix  of  the  dentin  contains  two  distinct 
substances,  one  forming  a  thick  and  uniform  coating  about  each  tubule, 
so  that  the  dentin  is  traversed  by  as  many  of  the  coatings  or  sheaths 
of  Neumann  as  there  are  odontoblastic  processes.  In  addition,  the 
enclosing  sheaths  are  united  laterally  with  one  another  by  a  material 
akin  to  or  identical  with  that  forming  the  sheaths  of  Neumann.  It  is 
believed  that  the  substance  of  these  sheaths  is  a  transitional  product 
which,  when  fully  calcified,  becomes  the  basis-substance  of  dentin. 
Subjected  to  the  action  of  acids,  the  material  of  Neumann's  sheaths  is 
foimd  much  more  resistant  than  the  basis-substance  of  dentin. 

The  relation  of  dentin  to  the  odontoblasts  is  that  of  a  formed  product. 
So  far  as  disease-processes  are  concerned,  the  formed  material  of  the 
dentin  must  play  a  passive  part ;  although  this  may  and  probably  does 
not  apply  to  the  transitional  substance,  the  sheaths  of  Neumann,  as 
being  but  a  partially  formed  tissue  it  is  susceptible  of  constructive 
change.  Disorders  which  involve  constructive  nutritive  changes  in 
the  dentin  can  evidently  be  only  associated  with  its  vital  parts,  which 
are  the  dentinal  filaments,  prolongations  of  the  peripheral  cells  of  the 
pulp.  It  follows,  therefore,  that  all  nutritional  changes  which  occur  in 
the  dentin  are  directly  the  result  of  a  physiological  or  pathological 
process  in  the  pulp ;  and  associated  disease-conditions  are  not  diseases 
of  dentin,  strictly  speaking,  but  are  diseases  of  the  pulp. 

Classification. — What  are  termed  diseases  of  the  dentin,  meaning 
diseases  in  which  the  structure  of  the  dentin  undergoes  changes,  are 
divisible  into  two  classes — constructive  diseases  and  destructive  dis- 
eases. The  constructive  diseases  in  an  accurate  classification  can  only  be 
those  conditions  in  which  formative  structural  changes  occur  about  the 
dentinal  tubuli.  As  transitional  material  exists,  no  doubt,  also  about  the 
transverse  as  well  as  the  longitudinal  processes,  and  as  partially  calcified 
tissue  probably  occupies  many  of  the  interglobular  spaces,  at  least  the 
possibility  must  be  assumed  of  a  change  which  could  affect  all  of  this 

260 


SECONDARY  DEPOSITS.  261 

material — i.  e.,  transform  it  from  a  partially  to  a  completely  calcified 
material. 

The  formation  of  adventitious  deposits  of  dentin  or  modified  dentin 
on  the  surface  or  in  the  substance  of  the  dental  pulp  is  clearly  a  pro- 
cess to  be  included  under  the  diseases  of  the  pulp  proper. 

The  destructive  diseases  of  the  dentin  are  divisible,  according  to  their 
causation,  into,  first,  those  due  primarily  to  chemical  action — erosion  and 
caries  ;  secondly,  those  due  to  physical  forces — abrasion  ;  thirdly,  those 
due  to  vital  causes — a  resorption.  In  all  of  these  the  basis-substance 
of  the  dentin  must  be  regarded  as  playing  a  passive  part — it  is  a  formed 
material  being  acted  upon. 

Abrasion  of  the  Dentin. 

The  nature  and  character  of  abrasion  of  the  teeth  have  been  discussed 
under  the  head  of  affections  of  the  enamel.  Its  progress  is  more  rapid 
than  is  that  of  enamel  abrasion.  It  is  usually  attended,  particularly  in 
cases  of  abrasion  about  the  necks  of  the  teeth,  by  an  increase  in  the 
sensitivity  of  the  dentinal  fibrillse,  and  pulp  reaction. 

Erosion  of  Dentin. 
The  solution  or  destruction  of  dentin  in  the  progress  of  erosion  ap- 
pears to  be  much  slower  than  its  progress  in  enamel ;  as  in  abrasion, 
a  heightened  sensitivity  of  the  dentinal  fibrillse  is  common. 

Secondary  Deposits. 

It  is  noted  in  both  abrasion  and  erosion,  particularly  if  the  progress 
of  the  affections  be  slow,  that  the  dentin  undergoes  changes  in  appear- 
ance which  are  quite  characteristic  ;  instead  of  having  the  semi-opaque- 
ness of  the  dentin,  this  tissue  acquires  a  horn-like  translucency.  When 
the  teeth  are  broken  open  it  is  common  to  find  the  pulp  has  receded 
from  its  position  opposite  the  abrasion  or  erosion,  the  area  of  w^ithdrawal 
being  occupied  by  a  deposit  of  dentinal  substance  upon  the  wall  of  the 
pulp-cliamber.  In  cases  of  coronal  abrasion  the  deposit  may  be  uniform, 
reducing  the  size  of  the  pulp-chamber  at  all  aspects. 

It  is  the  change  from  opacity  to  translucency  which  is  the  notable 
feature.  This  change  is  also  noted  normally  in  the  dentin  of  aged 
persons.  It  has  been  emphasized  by  Miller^  that  the  opacity  of  the 
dentin  is  due  to  the  differences  between  the  light  refractive  index  of  the 
basis-substance  of  the  dentin  and  that  of  the  dentinal  tubuli.  Were  both 
of  these  of  uniform  composition,  the  dentin  would  be  translucent.  It  is 
a  rational  inference,  therefore,  that  the  nearer  to  a  uniform  composition 
the  dentin  attains  the  more  translucent  it  becomes.      Now,  as  it  is 

^  Micro-oryanisms  of  the  Human  Mouth. 


262  DISEASES  OF  THE  DENTINE. 

physiologically  out  of  the  question  that  the  basis-substance  or  formed 
dentin  should  become  identical  with  the  contents  of  the  dentinal  tubuli, 
there  is  but  one  inference,  which  is,  that  the  tubuli  acquire  the  nature 
of  the  formed  dentin.  It  is  stated,  in  objection  to  this  opinion,  that  if 
the  dentin  be  acted  upon  by  dilute  acids,  it  becomes  translucent.  In 
this  immediate  connection  Miller  ^  noted  that  the  zone  of  translucency 
(see  Chapter  XIV.)  in  dental  caries  was  not  caused  by  decalcification,  as 
that  portion  of  the  dentin  contained  an  excess  of  calcium  salts.  These 
facts  are  in  themselves  sufficient  to  indicate  that  the  appearance  of  trans- 
lucency in  dentin  is  due  to  changes  which  obliterate  the  dentinal  tubuli  ; 
inferentially  which  cause  calcification  in  the  sheaths  of  Neumann  and 
a  recession  of  the  odontoblastic  processes.  As  a  matter  of  fact,  the  den- 
tinal tubuli  certainly  do  normally  decrease  in  calibre  with  age. 

Positive  data  are  wanting  as  to  the  direct  causes  of  the  appearance  of 
translucency  and  as  to  exactly  how  the  translucent  dentin  differs  from 
ordinary  dentin  in  anatomical  and  chemical  composition.  From  the 
examples  cited,  however,  the  evidence  points  to  a  constructive  reac- 
tion of  the  protoplasmic  portions  of  the  dentin,  to  a  continued  stim- 
ulus ;  it  is  a  physiological  defence  of  the  pulp.  It  is  an  expression 
of  cell-stimulation  which  evinces  itself  in  a  heightened  functional 
activity — /.  e.,  increased  dentin-formation ;  the  hypersensitivity  of  the 
dentin  is  another  evidence  of  increased  functional  activity.  A  similar 
or  identical  process  is  noted  in  connection  with  what  is  called  the  spon- 
taneous arrest  of  dental  caries  (see  Chapter  XIV.). 

Resorption  of  Dentin. 

Some  of  the  features  of  this  process  will  be  discussed  under  the  head 
of  diseases  of  the  pericementum,  "  resorption  of  the  roots  of  permanent 
teeth."  The  normal  resorption  of  the  roots  of  the  temporary  teeth  and 
the  resorptions  which  occur  upon  the  root-surfaces  of  implanted, 
replanted,  or  transplanted  teeth,  are  a  species  of  phagocytosis ;  the 
tooth-tissue  being  removed  piecemeal  through  the  action  of  cells — odonto- 
clasts— which  are  in  all  probability  modified  leucocytes.  A  similar  pro- 
cess is  sometimes  noted  when  the  tissues  about  the  gum-margin  and  the 
marginal  pericementum  are  in  a  state  of  localized  irritation  or  inflam- 
mation.^ In  interdental  spaces  where  large  fragments  of  wooden  tooth- 
picks have  been  broken  off,  there  has  been  observed  a  deep  erosion  in 
the  cementum  and  in  the  dentin  of  the  tooth,  the  enamel  apparently  being 
unaffected.  The  appearances  in  no  wise  resemble  those  of  caries.  In 
one  case  such  an  accident  as  cited  resulted  in  resorption  of  the  lateral 
neck-walls  of  an  upper  cuspid  and  bicuspid,  exposing  the  pulp-chamber 
in  a  few  weeks. 

^  Micro-organisms  of  the  Human  Mouth.  ^  American  Sijstem  of  Dentistry,  vol.  i. 


RESORPTION  OF  PULP-CHAMBER    WALLS.  263 

Black  ^  speaks  of  the  process  as  resulting  from  mild  irritation  of  the 
soft  tissues,  stating  that  as  soon  as  pus  has  formed  the  absorptive  process 
ceases.  These  absorptions  have  been  noted  when  the  evidences  of  trau- 
matic injury  were  marked,  there  being,  however,  no  evidences  of  pus- 
formation.  These  Avere,  in  all  probability,  cases  of  phagocytic  reaction  in 
which  the  dental  tissues  were  secondarily  involved.  The  exact  nature  of 
the  solvent  formed  by  the  cell,  which  brings  about  the  solution  of  hard 
tissues,  is  not  known.  Krause  has  suggested  that  it  may  be  lactic  acid. 
So  far  as  the  nature  of  the  process  can  be  made  out,  it  is  due  to  the  action 
of  multinucleated  phagocytes,  which  attach  themselves  to  any  substance 
to  be  removed,  bone,  dentin,  etc.,  and  resorption  follows. 

Resorption  of  Pulp-chamber  Walls. 

GaskelP  has  reported  a  case  where  a  central  incisor  entirely  free 
from  caries  exhibited  on  its  palatal  aspect  a  pinkish  tinge,  which 
increased  in  depth  until  the  enamel  overlying  crushed  in,  revealing 
the  pulp  of  the  tooth  lying  immediately  beneath ;  there  had  been  a 
resorption  of  a  large  mass  of  the  dentin  lying  between  the  pulp  and 
the  enamel.  The  pulp  was  removed  and  the  tooth  filled.  No  history 
is  given  as  to  the  condition  of  the  root,  whether  resorption  had 
occurred  there  or  not.  Shortly  after,  the  adjoining  central  incisor 
exhibited  a  like  pink  coloration,  which  increased,  leading  to  the  infer- 
ence that  resorption  was  in  progress  in  this  tooth  also.  At  the  sugges- 
tion of  E.  C.  Kirk  the  patient  received  continued  doses  of  arsenic  iodid 
and  the  compound  syrup  of  the  hypophosphites,  in  the  hope  of  inducing 
a  general  and  local  constructive  metamorphosis.  This  treatment  was 
followed  by  a  gradual  disappearance  of  the  pink  coloration,  an  evidence 
of  a  redeposition  of  dentin.  In  the  absence  of  histological  data  it  is 
impossible  to  state  just  what  was  the  nature  of  the  repair-tissue  in 
this  case. 

^  American  System  of  Dentistry,  vol.  i. 

^  Proc.  Academy  of  Stomatology,  Phila.,  1895. 


CHAPTER  XII.  (Continued). 
DENTAL  CARIES. 

The  last  member  of  the  group  of  destructive  diseases  of  dentin  is 
the  all-important  one  of  dental  caries,  the  most  universal  of  all  diseases, 
and  one  from  which  but  few  civilized  persons  are  entirely  exempt. 

Definition. — Dental  caries  may  be  defined  as  a  progressive  molecu- 
lar destruction  of  the  calcic  tissues  of  the  teeth,  the  first  stage  of  which  is 
a  solution  of  the  calcium  salts  by  lactic  acid  ;  the  second,  the  dissolution 
of  the  organic  matrix  through  the  agency  of  saprophytic  fungi.  Defini- 
tions have  varied  according  to  the  contemporary  knowledge  of  the  etiology 
and  pathology  of  the  disease  ;  the  above  is  a  pathological  definition. 

History. — Examinations  of  crania  show  the  disease  to  be  certainly  as 
old  as  semi-civilization,  and  when  more  data  are  obtainable  it  will,  no 
doubt,  be  found  even  older.  The  skull  of  a  mummy  in  the  British 
Museum,  dating  2800  B.  C,  exhibits  well-marked  caries  and  other 
dental  diseases.  Caries  appears  in  the  teeth  of  the  skulls  of  all 
peoples,  no  matter  what  their  degree  of  civilization,  provided  their 
dietary  included  cooked  starchy  foods. 

The  explanations  as  to  the  nature  of  dental  caries  have  undergone 
changes  parallel  with  the  advances  of  the.  collateral  sciences  of  surgery. 
In  each  age  or  generation  theories  as  to  the  origin  and  natural  history 
of  dental  caries  have  reflected  the  contemporary  state  and  condition  of 
the  science  of  pathology ;  with  a  modification  of  the  theories  of  path- 
ology have  come  changes  of  conception  as  to  the  essential  nature  of  the 
dental  disorder.  At  the  present  time  the  etiology — at  least  the  direct 
etiology — of  dental  caries  constitutes  one  of  the  best  examples  in  all 
medicine,  of  absolutely  demonstrable  scientific  facts. 

In  its  indirect  etiology,  and  in  some  features  of  its  pathology  and 
morbid  anatomy,  there  is  much  left  to  be  discovered ;  although  Miller 
has  settled  beyond  doubt  the  question  of  its  direct  causation.  Mil- 
ler's discoveries  and  demonstrations  were,  as  all  great  discoveries  in 
any  field  of  science,  the  outcome,  or  an  evolution  from  all  that  had 
gone  before.  Theories  were  partially  formulated  and  set  forth  by  pre- 
vious investigators,  but  it  was  he  who  furnished  what  science  rigorously 
exacts  from  all  her  workers — direct  and  complete  demonstration  sub- 
stantiating a  formulated  theory. 

Investigations  and  opinions  prior  to  the  writings  of  John  Hunter, 
interesting  though  many  of  them  be,  are  necessarily  purely  speculative 

264 


HISTORY.  265 

in  nature,  for  the  reason  that  before  Hunter  pathology  bore  but  a  faint 
resemblance  to  a  science,  as  science  is  now  understood.  Hunter,^  while 
apparently  inclined  to  classify  dental  caries  with  inflammatory  disturb- 
ances, had  sufficient  doubt  of  such  a  position  to  note  that  caries  began 
upon  the  outsides  of  teeth.  The  next  English  writers  upon  odon- 
tography, Fox  and  Bell,  both  regarded  dental  caries  as  an  inflammatory- 
disturbance,  Fox  believing  that  the  disease  attacked  first  the  "  lining 
membrane  "  of  the  pulp-chamber,  and  that  the  dentin  deprived  of  its 
source  of  nutrition  died  and  disintegrated.  BelF  vigorously  combated 
the  theories  of  his  predecessors,  and  set  forth  positively  that  caries 
always  began  upon  the  periphery  of  the  dentin,  maintaining  that  the 
white  and  colored  spots  upon  enamel  arose  secondarily,  and  were  evi- 
dences of  underlying  carious  dentin.  Also,  that  caries  was  dental  gan- 
grene, and  proceeded  from  the  periphery  toward  the  pulp.  He  believed 
that  as  soon  as  the  pulp  and  crown  were  destroyed  the  caries  ceased,  and 
that  the  roots  became  of  the  nature  of  foreign  bodies  and  were  cast  oflP. 

Until  1830  nearly  all  writers  subscribed  to  a  greater  or  less  extent 
to  the  inflammatory  theory  of  caries,  which  received  its  final  blow 
in  the  observation  that  the  natural  crowns  of  teeth  which  had  been 
mounted  on  plates  decayed.  The  only  vestige  remaining  at  the  present 
of  a  belief  in  the  inflammatory  theories  of  dental  caries  is  the  writings 
of  Bodecker  and  Abbott,  although  their  opinions  have  a  broader  founda- 
tion than  those  of  the  older  observers  mentioned. 

These  theories  may  all  be  set  aside,  since  it  is  recognized  that  dental 
caries  proceeds  in  teeth  whose  dentin  has  been  deprived  of  its  source 
of  nutrition.  It  occurs  in  pulpless  teeth  ;  in  human  and  other  teeth 
mounted  upon  plates ;  and,  moreover,  may  be  artificially  produced  out- 
side of  the  mouth. 

The  next  theory  was  radically  different  from  the  foregoing.  In 
1835  Robertson,  of  Birmingliam,  England,  advanced  the  opinion,  based 
upon  his  observations,  that  it  "  is  to  chemical  and  not  to  inflammatory 
action  that  the  destruction  of  the  teeth  must  be  attributed."  The 
author  points  out  forcibly  the  errors  and  fallacies  of  previous  writers. 
He  states  that  ^  "  Particles  of  food  retained  in  fissures  and  imperfections 
of  the  teeth  and  in  the  spaces  between  the  teeth  undergo  a  process  of 
decomposition  and  acquire  the  property  of  corroding,  disuniting,  and 
therefore  destroying  the  earthy  and  animal  substances  of  which  the 
teeth  are  composed." 

John  Tomes,  a  little  later,  was  the  first  to  record  microscopic  exam- 
inations of  carious  dentin.     He  described  the  transparent  zone  lying 

^  Practical  Treatise  on  Diseases  of  the  Teeth,  1778. 

2  Bell  on  The  Teeth,  Phila.,  1830. 

*  Robertson,  A  Practical  Treatise  on  the  Human  Teeth,  2d  ed.,  Phila.,  1839. 


266  DENTAL  CARIES. 

between  the  carious  and  non-carious  dentin,  and  observed  and  pointed 
out  also  the  dentinal  fibrillse.  He  announced  the  very  significant  fact  in 
relation  to  caries,  that^  if  blue  litmus  paper  be  applied  to  a  carious 
cavity  it  is  at  once  reddened,  which  furnishes  evidence  of  the  presence 
of  an  agent  capable,  if  unresisted  by  the  vitality  of  the  dentin,  of 
depriving  the  tissue  of  its  earthy  constituents,  leaving  the  "  gelatin  to 
undergo  a  gradual  decomposition  favored  by  the  heat  and  moisture  of 
the  mouth." 

Tomes  first  established  the  essentially  chemical  character  of  some 
features  of  caries.  The  character  of  the  acid  and  its  localization  were, 
however,  not  ascertained. 

The  electro-chemical  theory  of  Bridgeman  was  the  next  hypothesis 
advanced ;  from  observation  he  noted  that  caries  was  more  frequent  in 
moist  than  in  dry  mouths,  and  that  caries  occurred  more  readily  about 
some  types  of  fillings  than  others.  He  believed  that  the  tissues  of  the 
gum  acted  as  the  negative  pole  of  a  battery,  the  enamel  of  the  tooth- 
crown  as  the  positive  element,  and  the  fluid  in  which  they  were  bathed 
as  an  electrolytic  fluid.  The  difference  in  the  electric  potentiality  of 
soft  tissues  and  the  tissues  of  the  tooth-crown  was  deemed  sufficient  to 
supply  the  conditions  of  a  battery.  Acid  substances  being  set  free  at 
the  positive  pole,  acted  as  decalcifying  agents.  The  source  of  the  acid 
was  not  held  to  be  from  the  electrolytic  fluid,  but  formed  by  acid  radicals 
set  free  from  their  combination  with  the  calcium  salts  of  the  enamel. 
It  will  be  seen  that  this  theory  is  substantially  the  basis  of  the  com- 
patibility theory  of  recurring  caries. 

It  has  been  maintained,  principally  by  S.  B.  Palmer,  that  the  cause 
of  the  recurrence  of  dental  caries  about  dental  fillings  is  due  to  the 
establishment  of  artificial  electro-chemical  relations  ;  the  readiness  with 
which  the  tooth-walls  succumbed  being  governed  by  the  extent  of  dif- 
ference of  electric  potentiality  between  filling-material  and  dentin. 
Recurrence  of  decay  appeared  to  occur  most  readily  about  gold  fillings, 
less  so  about  tin,  and  least  about  gutta-percha,  the  explanation  given 
being  that  the  difference  of  electric  potentiality  is  greatest  between  gold 
and  dentin,  and  least  between  dentin  and  gutta-percha.  The  fluids  of 
dentin,  called  of  poor  structure,  were  regarded  as  electrolytic  in  a  bat- 
tery of  which  one  element  was  the  filling  and  the  other  the  dentin ;  the 
moisture  of  the  dentin  being  electrically  decomposed,  oxygen  (and 
acids)  were  set  free,  Avhich  acted  as  the  destructive  agents.  These  opin- 
ions, set  forth  by  Palmer  in  1874,  were  reiterated  by  him  in  1894.^ 

Miller'^  examined  these  assumptions,  and  reported  a  long  series  of 
experiments  relative  thereto.  He  states  that  as  dentin  is  a  non- 
conductor it  cannot    form   an   element   of   a   battery ;  the  fluid   with 

1  Dental  Surgery,  1859.  ^  Dental  Cosmos,  Nov.,  1894.  =*  Tbid.,  1881. 


HISTORY.  267 

which  dentin  is  permeated  is,  however,  a  conductor.  "  It  is  always 
possible  to  produce  an  electric  current  by  means  of  two  liquids  and 
one  metal,  provided  that  both  liquids  are  conductors,  communicate 
freely  with  one  another,  and  act  differently  upon  the  metal.  Hence, 
an  amalgam  or  tin  filling  in  a  tooth  with  the  saliva  upon  one  side  and  the 
fluids  of  the  dentin  upon  the  other  would  produce  a  stronger  current 
than  with  gold."  "  Living  dentin  is  a  better  conductor  than  dead ; 
hence  in  such  case  metal  fillings  should  fiiil  sooner  in  contact  with  vital 
than  with  dead  dentin."  "  Assuming  that  for  the  production  of  an 
electric  element  it  is  only  necessary  that  one  of  them  be  more  easily 
acted  upon  chemically  than  the  other;  enamel  and  dentin,  dentin  and 
cementum,  are  such  substances ;  hence  a  tooth  is  a  galvanic  battery 
when  in  contact  with  saliva." 

Pieces  of  ivory  and  dentin,  having  the  different  filling  materials 
inserted  in  them,  were  suspended  in  dilute  acid  for  periods  of  weeks, 
and  at  the  end  of  that  time  all  were  found  aflFected  by  the  acid  in  about 
equal  degree ;  had  electrolytic  currents  been  generated  between  the 
metals  and  dentin  the  latter  would  have  been  acted  upon  more  vigor- 
ously in  some  cases  than  in  others. 

Prior  to  this  time  the  chemical  theory  of  dental  caries  had  received 
general  acceptance,  the  question  of  the  origin  of  the  acids  being  still 
in  doubt.  Before  1868  ^George  Watt  had  advanced  the  mineral-acid 
theory  :  that  decay  is  caused  by  the  action  of  mineral  acids  (nitric, 
hydrochloric,  and  sulfuric),  generated  in  the  mouth,  upon  the  calcic 
tissues  of  the  teeth.  Watt,  using  the  older  chemical  nomenclature, 
ascribes  the  origin  of  sulfuric  acid  to  be  from  H^S  generated  in  putre- 
factive processes  ;  it  is  acted  upon  by  oxygen  ;  sulfur  is  set  free,  which  in 
a  nascent  state  combines  with  oxygen,  forming  sulfur  dioxid,  in  the  pres- 
ence of  the  watery  saliva  becoming  SO3  (old  nomenclature),  sulfuric  acid. 

"  Hydrochloric  acid  may  be  free  in  the  mouth,  or  may  result  from 
the  decomposition  of  chlorids.  Chlorin  is  set  free,  which,  combining 
with  hydrogen,  forms  HCl."  ^ 

Nitric  acid  was  held  to  be  formed  from  the  ammonia  produced  in  the 
process  of  organic  decomposition  ;  decomposed  by  the  action  of  oxygen, 
nitrogen  oxids  are  formed,  one  of  them  being  nitric  acid. 

The  physical  appearance  of  the  carious  dentin  was  held  to  be  due 
to  the  offending  acid  ;  if  "  sulfuric  acid,  black  decay  was  produced  ;  if 
nitric,  white  decay ;  hydrochloric  acid  producing  the  yellow  and  brown 
decay."  ^ 

It  is  natural  that  in  the  country  of  Pasteur  the  organic  acids  and 
the  sources  of  their  origin  in  fermentation  should  be  advanced  as  the 
possible  causes  of  tooth-decalcification.     Magitot  pointed  out  that  the 

1  Chemical  Essays,  1868.  ^  Ibid.  » Ibid. 


268  DENTAL  CARIES. 

essential  phenomena  of  caries,  as  they  were  then  understood,  were  the 
same  in  natural  teeth  mounted  upon  plates  as  in  the  natural  organs 
in  situ  ;  proving  that  caries  is  intrinsically  independent  of  the  existence 
of  vitality.  By  immersing  teeth  in  solutions  of  sugar  undergoing  fer- 
mentative changes  he  found  that  decalcification  occurred.  Teeth 
immersed  in  solutions  of  sugar  in  which  fermentation  had  been  pre- 
vented by  boiling  the  solution  and  sealing,  or  by  additions  of  sufficient 
carbolic  acid,  remained  unaffected. 

Leber  and  Rottenstein,  in  1867,  first  called  attention  to  the  probable 
causative  association  of  bacteria  with  some  phases  of  dental  caries.  By 
staining  carious  dentin  with  iodin  the  dilated  dentinal  tubules  were 
shown  to  be  filled  with  granular  bodies,  which  they  recognized  as 
bacteria,  identifying  but  one  of  the  many  forms  of  oral  bacteria — the 
leptothrix.  They  deemed  an  initial  exposure  of  dentin  a  necessary  pre- 
liminary to  the  invasion  and  growth  of  the  leptothrix,  which  in  condi- 
tions of  lessened  resistance  gained  access  to  the  tubules  and  in  some 
undescribed  manner  caused  their  dilatation. 

The  question  of  the  recognition  of  the  presence  of  bacteria  directly 
resolves  itself  into  the  subject  of  special  staining.  Prior  to  the  work 
of  Koch,  presented  in  1881,  no  means  of  isolating  specific  bacteria  by 
special  cultures  and  staining  were  known,  and  it  is  remarkable  that  in 
the  same  year  the  essential  features  of  dental  caries  were  first  made 
out  with  some  degree  of  clearness. 

Milles  and  Underwood  (World's  Medical  Congress,  1881)  point  out 
clearly  and  at  length  the  different  appearances  produced  by  simple 
decalcification  of  dentin  and  those  by  dental  caries.  Speaking  of 
Magitot's  experiments,  they  say  :  "  We  assume  that  two  factors  have 
always  been  in  operation  :  (1)  the  action  of  acids,  and  (2)  the  action  of 
germs.  When  caries  occurs  in  mouths  it  is  always  under  circumstances 
more  favorable  to  the  action  of  germs  than  to  the  action  of  acids."  They 
believed  that  the  acids  necessary  for  the  decalcification  were  excreted  by 
the  germs,  which  utilized  the  dentinal  fibrill*  as  a  food-supply. 

It  will  be  seen  that  the  invasion  and  multiplication  of  organisms  in 
the  tubuli  were  held  as  the  antecedent  of  the  process  of  decalcification. 
The  deductions  of  these  gentlemen  were  drawn  from  data  not  derived 
from  the  methods  of  modern  bacteriology- — i.  e.,  special  stains  and 
special  cultures.  Moreover,  they  were  made  before  the  physiological 
chemistry  of  bacteria  was  even  partially  understood. 

In  1882  W.  D.  Miller,  of  Berlin,  announced  as  the  results  of  experi- 
ments conducted  by  him  that  he  believed  the  first  stage  of  dental  caries 
to  consist  of  a  decalcification  of  the  tissues  of  the  teeth  by  acids  which 
are  for  the  greater  part  generated  in  the  mouth  by  fermentation.  This, 
it  will  be  seen,  is  a  position  in  agreement  with  that  of  Leber  and  Rotten- 


HISTORY.  269 

stein,  rather  than  with  that  of  Milles  and  Underwood.  Miller's  experi- 
ments^ carry  conviction  with  them. 

Experiment  1. — Fresh  saliva,  mixed  with  starch  (1  :40)  and  kept  at 
blood-temperatnre,  invariably  became  acid  in  from  four  to  five  hours. 

Experiment  2. — A  glass  tube,  2  cm.  long  and  3  mm.  wide,  was  filled 
with  starch  and  fastened  to  a  molar  tooth  on  going  to  bed ;  the  next 
morning  the  contents  of  the  tube  had  a  strong  acid  reaction. 

Experiment  3. — When  mixture  was  heated  for  half  an  hour  at  100°  C. 
and  placed  in  an  incubator  it  did  not  become  acid  in  twenty-four  hours. 

Experiment  4. — AVhen  the  starch  alone  was  heated  to  150°  before 
mixing,  the  solution  became  sour  ;  hence  the  ferment  exists  in  the  saliva, 
and  not  in  the  starch. 

Experiment  6. — Carbolic  acid  was  added  to  saliva  and  starch  mix- 
ture to  ^  per  cent,  strength,  and  put  in  an  incubator  :  when  tested  in  a 
few  hours  no  acid  was  found,  but  sugar  was  in  solution. 

Expjeriment  7. — A  mixture  of  saliva  and  grape-sugar  was  subjected 
to  a  temperature  of  67°  C  for  twenty  minutes  (which  destroys  ptyalin, 
but  cannot  destroy  organized  ferments),  and  placed  in  an  incubator  for 
twenty  hours :  the  solution  became  acid,  hence  the  fermentation  was 
caused  by  an  organized  ferment. 

Experiment  8. — Several  drops  of  a  solution  of  starch  and  saliva  (1  :  40) 
were  put  in  each  of  several  sterilized  test-tubes  and  sterilized.  One 
tube  was  used  as  a  control.  One  tube  was  infected  with  carious  dentin  : 
in  twenty  hours  the  solution  was  acid.  From  this  tube  a  second  tube  was 
infected ;  from  the  second  a  third,  and  so  on  :  each  became  acid — /.  e., 
an  organized  and  reproductive  ferment,  producing  acid,  was  contained 
in  deep  layers  of  carious  dentin. 

Other  experiments  demonstrated  the  fungus  to  be  independent  of 
the  free  access  of  oxygen  for  its  development.  Infections  by  saliva  of 
the  above  named  mixture  made  before  and  after  a  vigorous  cleansing  of 
the  teeth  showed  that  the  amount  of  acid  produced  after  cleansing  was 
often  not  more  than  one-fourth  that  produced  by  the  saliva  before  cleans- 
ing the  teeth. 

Cultures  from  the  deeply  infected  dentin  showed  the  growth  of 
organisms  (Fig.  224)  identical  in  form  with  the  bacillus  acidi  lactici. 
Grown  upon  carbohydrates,  acid  solutions  were  produced  ;  grown  upon 
beef-extracts  without  carbohydrates,  no  acid  reaction  took  place. 

Sections  of  sound  dentin  were  placed  in  5  c.c.  of  a  neutralized  2  per 
cent,  solution  of  beef-extract.  In  a  second  test-tube  similar  sections 
were  placed  in  the  same  solution  with  the  addition  of  0.2  per  cent,  of 
cane-sugar ;  both  were  sterilized,  and  then  infected  with  a  pure  culture 
of  the  fungus  under  discussion.    After  weeks  the  first  tube  gave  no  acid 

^  Independent  Practitioner,  1884-'8o. 


270 


DENTAL  CARIES. 


Fig.  224. 


Fungi  from  carious  dentin.    (Miller 


reaction,  and  the  dentin  sections  gave  no  evidence  of  softening.  In 
the  second  tube,  that  containing  the  cane-sugar,  all  of  the  sections  were 
entirely  softened  within  three  weeks,  and  stained  sections,  mounted, 

showed  the  tubes  to  be  invaded  by 
organisms  and  dilated,  in  some  places 
the  walls  being  broken  down,  forming 
caverns. 

By  inducing  and  checking  fermen- 
tation after  a  mixture  of  saliva  and 
starch  had  acquired  an  acid  reaction, 
filtering,  and  accumulating  the  filtered 
acid  solution  until  a  litre  had  been 
obtained.  Miller  sought  to  determine 
the  nature  of  the  acid  present.  Its 
volume  was  reduced  over  a  water- 
bath  to  75  c.c. ;  a  few  drops  placed 
in  a  dilute  solution  of  methyl-violet 
produced  no  change — i.  e.,  the  acid  is  organic.  Concentrated  over  the 
bath  to  40  c.c,  the  solution  was  next  shaken  with  one  and  one-half  to 
two  litres  of  ether,  and  allowed  to  stand  until  the  ether  became  trans- 
parent ;  this  was  then  distilled  until  the  volume  was  reduced  to  50  c.c. 
The  filtered  solution  was  further  reduced  over  the  water-bath.  An  ex- 
cess of  freshly  prepared  zinc  oxid  was  added,  the  solution  boiled,  and 
water  added  until  the  reaction  became  neutral.  Filtered  again,  the 
solution  was  set  aside  until  crystallization  occurred ;  a  drop  placed 
upon  a  slide  under  the  microscope    showed  the  forms  (Fig.  225)  of 

crystals  of  zinc  lactate.  By  testing  the  molec- 
ular weight  of  the  washed  and  dried  crystals 
it  was  determined  clearly  that  the  substance 
was  zinc  lactate. 

Miller  obtained  lactic  acid  from  carious 
dentin  directly.  The  carious  dentin  of  seve- 
ral freshly  extracted  teeth  was  freed  from 
food-debris,  cut  in  fine  pieces,  placed  in  a  test- 
tube  with  1  c.c.  of  water,  and  2  drops  of  a  10 
per  cent,  solution  of  hydrochloric  acid  added. 
Twenty-five  c.c.  of  ether  were  then  added 
and  after  some  minutes  the  ether  holding  the  lactic  acid  present  in  solu- 
tion was  poured  off  and  left  standing  in  a  test-tube  twenty-four  to  forty- 
eight  hours,  until  the  solution  was  clear.  Filtered  and  evaporated,  a  few 
drops  of  distilled  water  and  zinc  oxid  were  added  :  crystals  recognizable 
as  those  of  zinc  lactate  formed. 

The  character  of  the  infecting  organisms  is  shown  in  the  following 


Fig.  225. 


HISTORY.  271 

manner  "a  beef-sugar  extract  is  infected  from  the  deep  layers  of  carious 
dentin  ;  the  solution  is  kept  free  from  extraneous  organisms  and  at  a 
temperature  of  37°  C.  The  solution  clouds  in  a  few  hours  ;  in  fifteen 
hours  the  fermentation  will  have  reached  its  most  active  state  ;  the  solu- 
tion soon  after  begins  to  clear,  and  a  flocculent  colorless  precipitate 
collects  as  a  sediment  upon  the  bottom  of  the  vessel.  The  sediment 
consists  of  cocci  and  micrococci,  single  or  in  chains  (Fig.  226)."    These 

Fig.  226. 

/  *_  /)     /I  n  V 


\^  "    '^ 


'^0>., 


fungi  cause  the  direct  splitting  up  of  sugar  without  the  formation  of 
carbon  dioxid,  CgHigOg,  a  molecule  of  glucose,  forming  2C3H6O3,  or 
two  molecules  of  lactic  acid. 

The  fungi  have  the  power  of  inducing  hydration  of  non-fermentable 
cane-sugar,  converting  it  into  fermentable  levulose  and  dextrose — 

Cane-sugar.  Levulose.  Dextrose. 

Miller  at  this  time  deduced  from  his  studies  that  the  nature  of  the 
carious  process  is  as  follows  :  "  Whenever  solutions  of  sugar  (nearly 
always  present  in  the  human  mouth)  stagnate  in  fissures  between  the 
teeth,  etc.,  they  must  become  acid.  The  acids  gaining  access  to  the  dentin 
decalcify  a  portion  of  that  tissue  ;  the  tubules  of  the  decalcified  dentin 
take  up  the  solutions  of  sugar  and  organisms  which  develop  independent 
of  the  access  of  air.  Flourishing  they  produce  lactic  acid  within  the 
tubules.  As  each  layer  of  dentin  becomes  softened  in  time,  the  micro- 
organisms follow  after,  continually  producing  new  acid." 

The  same  observer  has  added  much  to  this  basal  doctrine  since  his 
original  publication,  which  matter  is  considered  under  appropriate 
heads.  The  discoveries  set  forth  are  the  demonstrations  which  con- 
vinced the  dental  fraternity  that  the  essential  character  of  the  carious 
process  had  at  last  been  made  out.     There  are  matters  relative  to  the 


272  DENTAL  CARIES. 

etiology,  pathology,  and  clinical  history  of  caries  which  still  require 
elucidation. 

Williams  ^  has  supplied  a  missing  link  in  the  pathology  and  mor- 
bid anatomy  of  caries  by  demonstrating  the  details  of  caries  of  enamel. 
Black  ^  has  exploded  several  fallacious  ideas  previously  held  as  to  the 
etiology  and  clinical  history  of  caries,  and  paved  the  way  for  a  better 
understanding  of  the  predisposing  causes  and  variations  of  the  active 
causes  of  dental  caries. 

Some  of  the  features  of  the  morbid  anatomy  of  dental  caries,  as 
shown  by  Miller,  have  been  expounded  by  Heitzmann,  Bodecker,  and 
Abbott,  who  represent  the  contemporary  school  of  believers  in  the  in- 
flammatory origin  of  dental  Caries.  The  substance  of  the  opinions  of 
these  gentlemen  is  that  dental  caries  consists  in  a  return  of  the  dentin 
to  its  embryonic  condition.  The  observation  that  dental  caries  may  be 
artificially  produced  and  occurs  in  dead  dentin,  exhibiting  the  same 
features  as  ordinary  carious  dentin,  is,  of  course,  the  death-blow  to  this, 
inflammatory  theory. 

1  Dental  Cosmos,  1897.  ^  Ibid.,  1895. 


CHAPTER  XIII. 

DENTAL  CARIES:    ITS  CAUSES  AND  CLINICAL  HISTORY. 

The  causes  of  deutal  caries  are  both  predisposino^  and  exciting. 
Each  of  these  again  may  be  subdivided  into  general  and  local. 

Exciting  Causes. 

Although  it  is  usual  to  discuss  the  predisposing  causes  of  a  particu- 
lar disease  before  passing  to  a  description  of  its  exciting  causes,  the 
predisposing  causes  of  dental  caries  are  made  more  clear  when  the  nature 
of  its  exciting  causes  is  first  understood. 

It  has  been  demonstrated  (see  Chapter  XII.)  beyond  reasonable 
doubt  that  the  direct  exciting  cause  of  dental  caries  is  lactic  acid.  A 
discussion  of  the  exciting  causes,  therefore,  involves  the  full  consid- 
eration of  the  conditions  of  lactic  fermentation  in  the  human  mouth. 
This  includes  two  factors :  first,  the  substances  out  of  which  lactic 
acid  is  formed  ;  and,  second,  the  organisms  which  cause  the  trans- 
formation. 

Lactic  acid  is  formed  out  of — /.  e.,  requires  for  its  production  the 
presence  of — substances  identical  with,  or  which  are  under  the  conditions 
of  the  mouth  converted  into,  glucose,  C^I{^2^^^'  These  are  the  three 
groups  of  carbohydrates — glucoses,  CgHjaOg,  saccharoses,  CigHjjOn,  and 
amyloses,  CgH,,,©,.  Those  most  common  in  the  human  dietary  are 
grape-sugar  or  dextrose,  and  fruit-sugar  or  levulose,  in  the  glucose 
group ;  cane-sugar  in  the  saccharose  group  ;  starch,  cellulose,  and  gum 
in  the  amylose  group. 

Cane-sugar  becomes  converted  by  hydration  into  the  two  fermentable 
carbohydrates  levulose  and  dextrose,  both  having  the  same  composition, 
CgHigOg.  This  hydration  is  brought  about  by  the  action  of  organized 
ferments,  such  as  ptyalin  and  amylopsin,  which  convert  starch  into 
glucose, 

CgH,A^H,0  =  CgH,A- 

starch  Glucose. 

In  order  to  effect  the  localized  and  persistent  fermentation  of  car- 
bohydrates necessary  for  the  production  of  dental  caries,  the  question 
of  lodgement  of  ferments  and  fermentable  materials  is  all   important. 

18  273 


274  DENTAL  CARIES. 

Given  points  of  lodgement  (see  Predisposing  Causes  of  Caries)  with  the 
presence  of  fermentable  material,  the  next  factor  is  the  existence  and 
proliferation  of  the  ferment.  Soluble  carbohydrates,  as  cane-sugar 
(saccharose),  lactose,  and  glucose,  soluble  in  saliva,  have  their  solutions 
carried  into  all  spaces  in  and  about  the  teeth  ;  and  if  ferments  be  pres- 
ent, organized  ferments  as  bacteria,  the  solutions  furnish  a  food-supply 
to  these  organisms.  Insoluble  or  but  partially  soluble  carbohydrates,  on 
the  other  hand,  alter  the  conditions.  The  eifects  of  the  general  oral  dis- 
tribution of  soluble  carbohydrates  may  be  seen  in  the  mouths  of  con- 
fectioners, who  work  amid  sugar,  in  which  evidences  of  general  fer- 
mentation— the  widespread  decalcification  of  enamel  and  dentin — are 
observed.  The  same  eifects  are  apparent  in  children  who  are  allowed 
to  use  sugars  unstintedly. 

Perfectly  soluble  carbohydrates  are,  however,  in  the  majority  of 
cases  washed  away  by  currents  of  saliva,  and  are  in  all  proba- 
bility removed  almost  entirely  from  about  the  teeth  under  normal 
conditions.  On  the  contrary,  insoluble  carbohydrates,  as  solid  sub- 
stances, are  not  washed  away,  except  mechanically,  unless  they  are 
transformed  into  soluble  substances  and  are  in  situations  where  they 
can  be  subjected  to  the  irrigating  force  of  the  saliva.  It  is  with  these 
substances  that  the  process  of  caries  is  probably  most  directly  asso- 
ciated. 

Caries,  as  has  been  pointed  out,  is  not  entirely  a  disease  of  civiliza- 
tion ;  some  savage  and  barbarous  races  are  aifected,  and  ancient  races 
have  also  been  affected.  It  is,  however,  largely  a  disease  of  civilization 
and  semi-civilization ;  so  that  the  causes  of  its  prevalence  are  to  be 
sought  for  in  the  artificial  environment  of  civilization.  A  notable 
difference  between  civilized  and  uncivilized  races  is  in  food-habit ;  in 
this  connection,  the  food-habit  as  regards  carbohydrates  is  referred  to. 
Judging  from  the  data  thus  far  presented  by  dental  ethnologists,  the 
barbarous  and  semi-civilized  races  which  suffer  from  dental  caries 
appear  to  be  those  whose  dietary  includes  cooked  starches. 

Starches  in  a  raw  state,  in  uncooked  vegetables,  are  combined  with 
fibrous  vegetable  tissue,  the  starch  being  enclosed  iu  capsules  of  cellu- 
lose. The  starch  is  not  in  condition  to  agglutinate ;  its  containing 
structures  crushed  by  the  teeth,  set  free  some  of  the  starch-particles, 
which  are  mechanically  separated  from  one  another ;  these  particles, 
acted  upon  by  the  ptyalin  of  the  saliva,  are  hydrated,  becoming  glucose. 
The  masses  are  in  large  part  or  wholly  washed  away  by  the  saliva  and 
mechanically  carried  away  by  the  vegetable  cellulose  of  plant-skins,  etc. 
By  cooking,  the  cellulose-coverings  of  the  starch-particles  are  burst ; 
the  starch-particles  are  set  free  and  collect  in  glutinous  masses,  which 
when  taken  as  food  are  in  condition  to  collect  and  remain  in  spaces. 


PREDISPOSINO   CAUSES.  275 

fissures,  etc.,  where,  being  acted  upon  by  ptyuliu,  glucose  is  formed, 
furnisliing  localized  fermentable  masses.  There  is  another  important 
consideration  in  this  connection  :  many  food-substances,  notably  fats, 
are  taken  at  a  temperature  at  which  they  are  wholly  or  nearly  fluid ; 
when  taken  into  the  mouth  the  reduction  of  temperature  and  other 
conditions  lead  to  their  collection  on,  around,  and  between  the  teeth, 
which  collections  not  only  undergo  changes  themselves,  but  servx'  as  a 
retaining  medium  for  other  debris. 

The  second  factor  in  fermentation,  the  first  being  the  fermentable 
material,  is  the  ferment  itself.  The  conditions  of  the  human  mouth, 
under  normal  circumstances  containing  food-debris,  an  abundance  of 
water,  dead  tissue,  and  a  constant  temperature,  are  such  as  to  permit 
the  growtli  of  numerous  micro-organisms.  Variations  in  the  conditions 
present  favor  or  deter  the  development  of  some  forms.  Until  the 
physiology  of  all  the  oral  bacteria  is  clearly  made  out,  the  nature 
of  the  conditions  favorable  or  deterrent  to  the  active  growth  of 
definite  forms  can  be  but  partially  understood.  One  essential  to  the 
growth  of  the  lactic  ferment  or  ferments  is  of  tolerably  constant 
presence  in  the  mouth,  and  yet  the  extent,  nature,  and  rajiidity  of 
progress  of  dental  caries  vary  widely  in  diiferent  individuals  and 
apparently  in  different  teeth  of  the  same  individual,  and  at  different 
times  in  the  same  person.  This  leads  to  the  inference  that  there  are 
conditions  which  fiivor  the  growth  of  lactic  ferments,  and  others  which 
check  it.  Noting  the  association  of  the  rapid  progress  of  dental  caries 
with  general  disease-states,  it  is  inferred  that  these  latter  establish  oral 
conditions  which  modifv  the  growth  of  the  lactic  ferment.  Again,  in 
the  absence  of  evident  general  disturbances,  it  is  believed  that  local  oral 
conditions  which  favor  growth  are  established  and  disappear. 

Predisposing  Causes. 

Conditions  are  noted  which  appear  to  bear  a  constant  relationship 
to  the  progress  of  dental  caries ;  when  these  conditions  exist  caries 
is  liable  to  occur,  and  when  they  are  absent  it  is  usually  slight  or  ab- 
sent. These  conditions  are  both  general  and  local.  Many  of  them,  as 
just  pointed  out,  are  veiled  in  obscurity,  and  we  have  at  present  no 
means  or  data  for  determining  the  scope  of  their  action.  For  example, 
why  a  denture  almost  free  from  caries  for  thirty  years  or  more  should 
suddenly  fall  a  victim  to  the  disease,  in  the  absence  of  any  change  in 
the  food-habit  or  any  local  anatomical  changes,  and  with  no  ap]>arent 
alteration  in  general  nutrition,  is  beyond  our  knowledge.  It  is  rational, 
however,  to  infer  that  conditions  are  present  which  favor  the  unusual 
development  of  the  lactic  ferment.  The  problem  is  one  which  belongs 
in  the  category  of  pathological  chemistry  of  the  cells  of  the  entire  body. 


276  DENTAL  CARIES. 

GENERAL    PREDISPOSING   CAUSES. 

There  are  certain  conditions  in  which  caries  is  almost  certain  to 
increase.  The  most  constant  of  these  is  pregnancy.  Not  only  does' 
caries  increase  in  extent  during  gestation,  but  the  rapidity  of  its  prog- 
ress is  markedly  increased.  In  many  of  the  cases  there  is  a  notable 
change  in  the  dietary  of  the  individual  and  commonly  a  lack  of  the 
usual  hygienic  care,  which  serve  to  explain  the  increase  of  caries.  In 
the  absence  of  these  causes,  it  is  evident  that  the  explanation  must  be 
found  in  one  of  two  conditions,  or  in  a  combination  of  them.  Either 
attack  must  be  increased,  or  resistance  lessened,  or  both  occur  con- 
currently. 

The  question  of  resistance  is  the  resistance  of  the  tissues  of  the 
teeth.  It  has  been  stated  and  maintained  that  during  gestation  there 
is  a  lessening  of  the  calcium  salts  of  the  teeth,  the  reason  being  that 
calcium  salts  are  robbed  from  the  tissues  of  the  mother  to  suj)ply 
the  tissues  of  the  foetus,  and  that  the  dentin  suffered  as  do  the  bones  of 
the  body.  The  enamel  being  a  non-vital  tissue,  of  course  could  not 
be  affected,  although  even  decalcification  of  this  tissue  has  been  held 
to  occur  as  part  of  the  inverted  nutrition.  The  mechanism  through 
which  resorption  occurs  is  not  set  forth  by  believers  in  this  doctrine. 
This  process  might  act  in  one  of  two  ways ;  vital  cells,  of  course,  being 
a  necessity  for  the  hypothetical  process.  The  odontoblasts  upon  their 
surfaces  and  in  their  filaments  must  be  the  medium  through  which  the 
retrograde  metamorphosis  is  accomplished,  or  else  the  usual  resorptive 
cells  must  be  the  active  agents — multinucleated  odontoclasts.  I^s^ow,  as 
it  is  never  maintained  that  the  matrix  itself  loses  its  form,  it  is  evident 
that  the  cells  must  then  cause  resorption  through  the  dentin-substance. 
A  solvent  must  be  formed  capable  of  abstracting  the  calcium  salts  from 
the  dentin,  and  capable  of  acting  through  the  thickness  of  the  trans- 
formed matrix.  The  calcium  salts  taken  up  by  the  odontoblasts,  or 
odontoclasts,  must  pass  through  them,  to  be  taken  up  by  the  veins. 
It  was  also  held  that  after  the  period  of  lactation  a  redeposition  of  cal- 
cium salts  occurred  which  restored  the  original  composition  of  the 
dentin  The  mode  of  formation  of  dentin  and  the  character  of  its 
nutrition  are  in  themselves  sufficient  to  set  aside  any  such  hypothesis  as 
the  above.  In  addition,  Black  has  shown  '  that  there  is  no  evidence  to 
support  a  belief  in  the  lessening  of  the  amounts  of  calcium  salts  of  the 
teeth  during  pregnancy,  so  that  the  matter  of  calcium  resorption  during 
pregnancy  meets  the  fate  of  the  inflammatory  theory  of  caries.  It 
may  be  mentioned,  in  addition,  that  pulpless  teeth  appear  to  break 
down  rapidly  in  the  caries  of  pregnancy,  and  as  there  could  not  by  any 

^  Denial  Co,^mo%  1895. 


PREDISPOSING   CAUSES.  277 

possibility  be  a  retrograde  metamorphosis  of  dead  dentin,  the  amount 
of  calcium  salts  in  the  tissue  could  not  be  a  factor. 

The  remaining  factor  for  consideration  is  the  condition  of  the  vital 
parts  of  the  dentin.  To  what  extent  the  condition  of  tlie  dentinal 
filament  is  an  element  modifying  the  progress  of  dental  caries  is  not 
made  out.  Do  variations  in  the  physiological  condition  of  these  proto- 
plasmic filaments  influence  and  modify  the  progress  of  dental  caries? 
In  many  or  most  of  the  cases  of  outbreaks  of  caries  it  is  difficult  or 
impossible  to  disassociate  an  increase  in  the  local  causes  of  caries.  In 
pregnancy,  in  such  debilitating  diseases  as  typhoid  fever  and  tuberculosis, 
and  in  other  wasting  disorders,  there  is  unquestionably  an  increase  of 
dental  caries,  with  an  increased  rapidity  of  progress.  It  is  this  element 
of  the  comparative  rapidity  of  the  carious  process  which  leads  to  the 
inference  that  the  condition  of  the  vital  parts  of  the  dentin  is  a  govern- 
ing or  modifying  factor.  Caries  not  being  solely  a  chemical  process, 
the  solution  of  the  calcium  salts  being  but  one  phase  of  it,  and  the 
disorganization  of  the  dentin-matrix  another,  it  remains  to  be  deter- 
mined what  rdle  the  dentinal  protoplasm  plays.  It  succumbs  during 
the  progress  of  caries,  and  probably,  like  all  protoplasm,  offers  its 
vital  resistance  to  the  action  of  irritants.  Since  it,  as  other  proto- 
plasm, is  profoundly  aifected  by  the  conditions  of  general  nutrition, 
does  it  offer  a  lessened  resistance  to  the  carious  process?  'Clinical 
records  appear  to  indicate  that  it  does.  Being  at  the  extreme  peripheral 
nutritive  zone,  its  power  of  resistance  would  be  likely  to  be  much  less 
than  that  of  more  freely  nourished  parts,  those  having  a  vascular 
system. 

Similar  conditions  appear  to  prevail  in  the  aneemic  and  leukfemic 
states.  It  is  notorious  that  caries  runs  a  riotous  course  in  diabetic 
patients  (glycosuria);  the  formation  of  lactic  acid  in  the  mouths  of  these 
patients  is  abundant  and  widespread. 

Among  the  important  general  predisposing  causes  of  dental  caries 
must  be  placed  heredity.  Unquestionably  the  children  of  parents 
whose  teeth  have  succumbed  readily  to  dental  caries  are  prone  to  be 
aflFected  in  a  similar  manner.  Moreover,  in  many  of  these  cases  local 
conditions  (environment)  are  not  sufficient  to  account  for  the  lessened 
resistance ;  the  evidence  points  to  a  general  condition  underlying  the 
dental  vulnerability. 

LOCAL   PREDISPOSING    CAUSES. 

What  are  termed  the  local  predisposing  causes  of  dental  caries  are 
much  more  evident  than  the  general  ;  they  include,  first,  variations  in 
the  structure,  arrangement,  and  forms  of  the  teeth,  together  with  other 
local  anatomical  and  physiological  variations  ;  they  are  not  actual  causes, 


278  DENTAL  CARIES. 

but  favoring  conditions.  The  variations  of  structure  are  macroscopic 
and  microscopic,  and,  no  doubt,  variations  in  the  chemical  organization 
of  the  dental  tissues  also  have  a  part.  Any  variation  of  structure 
which  furnishes  a  space  in  which  fermentable  material  can  find  lodge- 
ment is  included  under  this  head.  The  first  of  these  includes  fissures 
of  the  enamel ;  these  are  lines  of  faulty  enamel-formation,  marking  the 
bases  of  the  cusp-segments  of  the  teeth.  Their  capability  of  acting  as 
elements  of  predisposition  is  in  proportion  to  their  depth  and  extent. 
They  are  most  marked,  as  a  rule,  in  the  lower  molars,  next  in  the  upper 
molars  and  bicuspids ;  next  in  the  lower  bicuspids.  Pits  are  another 
favorable  lodgement-place  for  debris  ;  these  are  found  most  frequently 
at  the  bases  of  the  enamel-girders  of  the  upper  incisors,  at  the  ex- 
tremities of  the  sulci  of  bicusjDids,  and  at  the  bases  of  the  anterior 
cusps  of  the  upper  molars,  and  marking  the  extremity  of  the  buccal 
sulci  of  the  lower  molars.  Many  of  these  enamel-defects  are  so 
slight  as  to  require  the  use  of  high-poAver  objectives  to  discover 
them,^  and  yet  are  sufficiently  large  to  furnish  lodgement  for  masses 
of  bacteria. 

There  is  another  feature  which  calls  for  consideration :  for  some 
time  after  the  full  eruption  of  the  teeth,  fragments  of  the  partially 
calcified  structure  known  as  Nasmyth's  membrane  are  attached  to  the 
teeth  and  occupy  the  depths  of  pits  and  sulci ;  they,  no  doubt,  furnish 
lodgement  for  ferments  and  fermentable  material. 

If  gross  or  even  minute  defects  in  enamel  leave  the  dentin  exposed 
at  some  point  or  points,  the  carious  process  is  correspondingly  favored. 
There  are  differences  in  the  structure  of  the  dentin  which  influence  the 
rapidity  and  nature  of  the  carious  process.  The  existence  of  intra- 
globular  spaces  permits  the  quick  progress  of  the  disease.  Differences 
of  anatomical  organization  of  the  dentin  itself  also  appear  to  affect  the 
resistance  offered  by  this  tissue. 

Chemical  analysis  of  the  calcium  constituents  of  dentin,  enamel,  ce- 
mentum,  and  bone  shows  the  mineral  basis  of  these  tissues  to  be  prob- 
ably a  phosphato-carbonate  of  calcium  (P04)6Ca,oC03  or  3((P04)2Ca3)- 
CaCOg;  that  is,  saturated  calcium  phosphat-carbonate  in  a  combina- 
tion which  corresponds  to  apatite  (P04)gCaiori2.^  This  mineral  sub- 
stance and  dentin  and  enamel,  all  show  different  rates  of  solubility  in 
dilute  acids,  the  mineral  substance  being  most  soluble.  In  animal 
tissues  the  calcium  salts  are  combined  with  an  albuminous  bases  ;  the 
nature  of  the  union  and  the  chemical  composition  of  the  "calcium 
albuminate"  have  not  been  made  out.  Williams^  has  shown  that  in  the 
enamel  there  are  two  substances  which  differ  in  relative  solubilities ; 
hence  it  is  a  natural  inference  that  although  both  may  have  the  same 

1  Williams,  Dental  Cosmos,  1897.  ^  Miller.  ^  Dental  Cosmos,  1895. 


PEEDISPOSING   CAUSES.  279 

chemical  composition  they  differ  as  to  the  molecular  arrangement  of 
their  constituents. 

The  human  teeth,  as  shown  by  Black/  do  not  exhibit  sufficient  vari- 
ations in  chemical  composition  to  account  for  the  differences  observed 
in  their  decalcification  during  dental  caries.  As  emphasized,  "  the 
variations  in  the  amounts  of  salts  in  the  deutin  are  not  enough  to 
explain  their  variations  in  hardness."  ^  The  hardness  and  solubility 
of  dentin  not  being  governed  by  the  amount  of  calcium  salts  present, 
the  differences  of  solubility  must  be  looked  for  in  the  nature  of  the 
union  between  the  calcium  salts  and  the  albuminous  base ;  that  is, 
it  is  a  question  of  anatomical  organization  of  the  formed  product  of  the 
dental  tissues.  "  In  the  case  of  a  chemical  union  between  the  organic 
and  inorganic  constituents  of  a  tooth  we  should  expect  to  find  the 
dentin  hard  or  soft  according  as  the  union  is  firm  or  unstable."  ^ 

The  hardness  or  softness  of  teeth,  the  amount  of  calcium  salts 
they  contain,  or  even  their  anatomical  alterations,  cannot,  as  shown 
by  Black,  prevent  the  advent  or  progress  of  dental  caries,  although 
they  undoubtedly  do  modify  its  character  and  rate  of  progress.  The 
forces  of  attack  being  equal,  a  poorly  organized  and  badly  formed 
tooth  will  succumb  sooner  than  one  perfectly  formed  and  of  com- 
pletely organized  tissues ;  this  law  is  constant  in  all  biology.  Of 
course,  such  gross  malformations  as  areas  of  dentin  marred  by  lack 
of  enamel-formation — honeycombed  teeth — offer  an  inviting  field  for 
dental  caries ;  and  yet  in  some  cases  such  spaces  may  permanently 
escape  caries.  If  the  active  causes  of  dental  caries  fail  to  assert  them- 
selves, the  predisposing  causes  signify  little  or  nothing.  However,  as 
the  active  causes  of  dental  caries  are  of  almost  universal  distribution,  it 
is  rare  that  such  tissue  as  described  escapes. 

Faults  of  Form. — The  outward  forms  of  the  teeth  determine  in  a 
marked  degree  their  vulnerability  to  dental  caries,  viewed  both  as  to 
the  separate  forms,  a  lesser  consideration,  and,  secondly,  to  the  influ- 
ence that  form  exercises  upon  the  contact  relationships  of  the  teeth. 

Teeth  of  faultless  histological  structure  may  invite  the  carious  pro- 
cess if  the  pits  and  depressions  which  lie  between  the  cusps  are  of  un- 
usual depth.  Teeth  of  this  description  are,  as  a  rule,  broad  upon  the 
occlusal  faces  as  compared  with  their  cervical  widths ;  hence  in  the 
dental  arch,  if  the  arrangement  be  normal,  each  tooth  is  separated  from 
its  fellow  at  the  neck  by  a  V-shaped  interspace.  Provided  such  teeth 
do  not  acquire  roughened  enamel-surfaces  from  the  action  of  acids, 
locally  generated,  or  administered  medicinally,  these  spaces  are  generally 
kept  free  by  the  fluids  of  the  mouth,  which  flow  freely  between  the 
buccal  and  lingual  cavities.     If,  however,  the  molar  teeth  are  cuboidal 

1  Dental  Cosmos,  1897.  ^  ]\iiiier.  3  Miller. 


280  DENTAL  CARIES. 

in  fornij  the  bicuspids  laterally  flattened  cylinders,  and  the  incisors 
and  cuspids  rectangular  in  section,  the  approximal  spaces  have  not  the 
V-shaped  and  natural  self-cleansing  forms,  but  exhibit  broad  contact- 
surfaces,  between  which  debris  collects  and  is  not  removed  by  the  saliva 
and  the  movements  of  the  lips,  cheeks,  and  tongue.  The  fibrous  stems 
of  vegetables  and  meat-fibres  also  tend  to  free  the  teeth  from  foreign 
matters ;  raw  vegetables,  such  as  celery,  and  tough,  fibrous  meats  per- 
form a  useful  service  in  this  direction. 

Arrangement  of  the  Teeth. — No  matter  what  the  forms  and  struc- 
ture of  the  teeth,  if  they  be  arranged  in  such  a  manner  that  uncleansible 
spaces  are  formed  between  adjoining  teeth,  a  predisposition  to  caries  is 
created.  When,  through  the  loss  of  a  tooth,  adjoining  teeth  so  alter 
their  positions  that  the  natural  cleansing  agencies  of  the  mouth  are 
inactive,  predisposition  to  caries  is  established.  Teeth  which  have  lost 
their  antagonists  are  particularly  prone  to  accumulate  debris.  This  is 
marked  in  cases  where  several  teeth,  as  the  lower  molars,  have  been 
lost ;  their  antagonists  become  the  seat  of  food-debris  deposit  and  of 
salivary  calculi,  and  sooner  or  later  suiFer  from  degeneration  of  the 
pericementum. 

Other  Local  Predisposing  Causes. — The  relative  position  of  the 
anterior  borders  of  the  masseter  muscle  with  the  teeth,  is  in  some  indi- 
viduals far  forward,  forming  about  the  buccal  surfaces  of  both  upper 
and  lower  third  molars  a  cavity  partially  marked  oif  from  the  gen- 
eral buccal  cavity.  These  spaces  are  but  little  affected  by  the  irriga- 
tion of  the  saliva,  and  are  out  of  reach  of  the  tip  of  the  tongue ;  hence 
food-ddbris  is  likely  to  collect  along  the  cervico-buccal  margins  of  the 
teeth. 

If  the  frsenum  of  the  tongue  has  its  attachment  abnormally  near  the 
tip,  the  organ  is  limited  in  its  normal  office ;  its  sweep  is  not  sufficiently 
free,  so  that  not  only  is  there  difficulty  in  mastication,  but  a  lessening 
of  tongue-cleansing  of  the  teeth,  a  double  cause  for  the  accumulation 
of  debris. 

Alterations  in  the  character  of  the  salivary  and  oral  secretions 
may  predispose  to  caries.  It  is  questionable  whether  the  saliva  itself, 
as  contained  in  the  acini  of  the  salivary  glands,  is  ever  of  acid 
reaction,  but  it  is  certain  that  it  is  usually  acid  in  reaction  as  found  in 
the  oral  and  buccal  cavities.  The  mucous  glands  of  the  lips  in  condi- 
tions of  irritation  produce  an  acid  secretion.  The  general  distribution 
of  acid  in  the  fluids  of  the  mouth  would  first  exercise  an  influence  as 
a  general  decalcifying  agent,  producing  roughness  or  at  least  loss  of 
polish  of  the  enamel-surfaces,  which  would  invite  caries  by  affording 
lodgement  for  food-debris.  In  mouths  showing  an  acid  reaction  of  the 
saliva  it  is  common  to  find  a  ropy  appearance  of  the  fluid,  particu- 


CLINICAL  HISTORY  OF  CARIES. 


281 


larly  on  the  floor  of  the  mouth.  Mucin  is  precipitated  by  lactic  acid, 
presumably  the  offending  substance  in  acid  saliva,  and  while  no  doubt 
the  part  played  by  the  coagulated  or  partially  coagulated  mucin  is  in 
the  formation  of  calculous  deposits,  yet  coagula  aid  in  the  retention  of 
food-debris.  In  the  same  manner,  catarrhal  conditions  of  the  mouth 
have  a  part  in  the  production  of  caries.  In  these  cases  there  is  an 
increased  secretion  of  mucin,  which  acts  when  coagulated  in  the 
manner  stated. 

Clinical  History  of  Caries. 

The  clinical  history  of  dental  caries  records  the  observable  phenomena 
associated  with  its  inception,  progress,  and  termination. 

INCEPTIOX    OF    caries. 

Caries  usually  begins  upon  the  occlusal  surfaces  of  the  molar  teeth, 
because  here  are  usually  found  those  defects  of  structure  named  under 
the  head  of  predisposing  causes  of  caries.  In  general  terms,  caries 
begins  in  situations  which  afford  the  most  marked  predisposition  to  it. 


Fig.  227. 


Fig.  228. 


Fig.  229. 


Fig.  230. 


Fig.  231. 


Fig.  232.  Fig.  233. 


Fig.  234. 


Fig.  235.  Fig.  236. 


Fig.  237. 


Fig.  238.  Fig.  239. 


Fig.  240. 


*'  The  situations  in  which  caries  appears  are  conveniently  divided  under 
four  heads  :  (1)  pits,  grooves,  and  fissures  of  the  enamel ;  (2)  proximal 
surfaces ;  (3)  smooth  surfaces  which  from  any  cause  are  habitually 
unclean  ;  (4)  necks  of  the  teeth,  at  or  near  the  junction  of  tlie  cement  or 
enamel "  (Black). 

Caries  appears  more  frequently  in  the  permanent  first  molars  than  in 
any  other  teeth.  Erupted  at  the  ages  of  from  five  and  one-half  to 
seven  and  one-half  years,  these  teeth  are  in  position  before  any  of  the 
temporary  teeth  are  lost ;  they  are  longer  subjected  to  the  attacks  of 


282  DENTAL   CARIES. 

caries-producing  conditions,  are  present  before  the  patient  has  learned 
to  vohintarilj  care  for  the  teeth,  and,  in  addition,  usually  present 
enamel-faults  or  configurations  which  aid  in  the  retention  of  food-debris. 
At  this  period  it  is  unusual  for  the  dietary  to  contain  the  substances- 
■which  act  as  mechanical  cleansers,  or  for  the  child  to  masticate  with 
sufficient  vigor  to  aid  this  end.  The  lower  first  molars  are  usually 
affected  before  the  upper,  the  latter  showing  caries  at  a  later  period 
(Figs.  227  and  228). 

The  upper  incisor  teeth,  erupted  next,  do  not,  as  a  rule,  exhibit 
marked  evidences  of  caries  so  soon  as  the  permanent  second  molars, 
erupted  years  after,  although  they  are  usually  affected  before  the  bicus- 
pids. The  lower  anterior  teeth  are  the  last  of  all  to  be  affected,  and  it  is 
common  to  see  the  six  lower  anterior  teeth  free  from  caries  years  after 
all  of  the  other  teeth  have  been  lost.  This  is  attributable  to  the  constant 
washing  these  teeth  receive  from  the  saliva  and 'to  the  mechanical  effects 
of  tongue-  and  lip-movement  and  mastication. 

If  a  deep  basilar  pit  exist,  as  it  frequently  does,  upon  the  lingual  sur- 
face of  the  upper  lateral  incisor  (Fig.  238),  it  marks  this  tooth  for  an  early 
victim.  The  approximal  surfaces  of  the  incisors  offer  inviting  condi- 
tions. It  will  be  remembered  that  the  disto-approximal  Myalls  of  the 
upper  incisors  are  much  more  rounded  than  the  mesio-approximal  walls  ; 
hence  these  flattened  surfaces  afford  a  more  ready  lodgement  for  d6bri& 
than  the  others.  In  the  upper  lateral  incisors  the  mesial  wall  has  fre- 
quently a  depressed  form,  inviting  the  beginning  of  caries  (Fig,  240). 

The  upper  bicuspid  teeth  are  next  in  point  of  vulnerability.  If 
enamel-fissures  exist  upon  the  occlusal  surfaces,  they  become  the  seat  of 
the  disease  (Fig.  231) ;  the  pits  marking  the  sulci-extremities  of  these 
teeth  usually  exhibit  caries  first.  Even  in  the  absence  of  these  defects, 
the  upper  bicuspids  are  affected  next  in  point  of  frequency,  the  nature 
of  the  contact  between  the  bicuspids,  and  between  bicuspids  and  first 
molars  furnishing  the  lodgement  for  debris. 

It  is  usual  to  find  caries  affect  the  distal  surface  of  the  upper  central 
incisor  some  time  after  the  disease  makes  its  appearance  on  the  mesial 
surface  of  the  adjoining  lateral  incisor  (Figs.  235  and  236).  For  a  period 
the  rounded  surface  is  kept  clean,  but  rarely  escapes  infection  for  long. 

The  mesial  walls  of  the  first  molars  are  affected  next  in  point  of  fre- 
quency, particularly  if  the  distal  wall  of  the  second  bicuspid  have  pre- 
viously become  carious.  If  the  occlusal  faces  of  the  lower  bicuspids  have 
defects  of  structure — pits,  or  in  the  second  bicuspids  fissures — they  become 
affected  (Fig.  232) ;  but  in  point  of  usual  occurrence  the  mesial  surfaces  of 
the  cuspids  appear  to  succumb  next.  The  somewhat  flattened  surface  in 
contact  with  the  rounded  distal  wall  of  the  lateral  incisor  may  invite  the 
condition,  or  infection  may  occur  after  the  appearance  of  caries  in  the 


CLISICAL  HISTORY  OF  CARIES. 


283 


Fig.  241. 


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DESCRIPTION   OF   CHARTS. 

These  charts  represent  the  number  of  carious  cavities  observed  in  one  hundred  persons,  and  the 
position  of  these  cavities  on  the  individual  surfaces  of  the  teeth.  There  are  five  columns  of  squares 
devoted  to  each  tooth  of  one  side  of  the  mouth,  representing  the  five  surfaces  as  shown  on  the  left 
hand.  The  number  of  cavities  in  the  surface  represented  is  shown  by  the  number  of  squares  dark- 
ened, so  that  the  effect  of  the  diagram  as  a  whole  gives  a  striking  picture  of  the  frequency  of  decay- 
in  the  individual  surfaces  of  the  several  teeth.  On  the  right  the  percentage,  or  the  number  per 
hundred  persons,  is  given  in  figures  calculated  to  the  first  decimal  point.  On  the  left  the  percent- 
age of  cavities  in  the  individual  teeth  for  all  surfaces  is  given  in  the  same  way.    The  cavities 


284 


DENTAL  CARIES. 


Fig.  242. 


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occurring  on  one  side  of  the  mouth  only  are  represented.  And  only  one  decay  In  an  individual 
surface  is  counted :  that  is,  if  two  or  more  pits  are  found  decayed  in  the  grinding  surface  of  a 
molar,  but  one  is  counted ;  and  the  same  rule  is  followed  with  all  of  the  surfaces. 

Charts  No.  1  and  2  (upper  and  lower  jaw)  are  made  up  from  my  records  of  fillings  for  628  per- 
sons of  all  ages,  and  therefore  represent  what  is  seen  in  practice  rather  than  the  actual  number 
that  may  occur. 

Charts  No.  3  and  4  (upper  and  lower  jaw)  are  made  from  100  of  my  own  patients  between  the 
ages  of  ten  and  twenty-five  years,  for  whom  I  have  filled  all  cavities  and  know  the  condition  at 
present.  They  represent  the  actual  number  of  cases  in  which  the  individual  surfaces  have  decayed 
in  these  100  persons.    (Black.) 


CLINICAL  HISTORY  OF  CARIES. 


285 


Fig.  243. 


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CLINICAL  HISTORY  OF  CARIES. 


287 


latter  tooth.  When  the  approximal  face  of  one  tooth  becomes  affected 
by  caries  it  is  usual  to  find  the  adjoining  tooth  also  affected  after  a 
period,  a  natural  inference  when  the  etiology  of  caries  is  remembered. 

It  is  unusual  for  the  third  molars,  upper  or  lower,  to  be  free  from 
caries  many  years  after  their  eruption.  Although  the  teeth  are  usually 
affected  in  about  the  order  given,  it  is  to  be  remembered  that  peculiari- 
ties of  structure,  form,  position,  and  personal  habits  modify  the  occur- 
rence and  progress  of  caries. 

The  preceding  charts  represent  records  made  by  Black  as  to  the 
relative  frequency  of  dental  caries.  "  First  molars,  being  extracted  in 
larger  proportion  than  other  teeth,  the  numbers  given  for  these  teeth  in 
the  tables  are  too  low." 

RAPIDITY    OF    PROGRESS. 

All  other  conditions  being  equal,  caries  progresses  most  rapidlv  in 
situations  where  the  persistent  lodgement  of  food-debris  and  bacteria  is 


Fig.  245. 


Section  of  human  bicuspid,  showing  commencement  of  caries:  a  a.\\Aa>,  appearances  caused  in 
enamel  and  dentin  by  the  acid  of  decay  ;  b  and  Ifi,  shreds  of  a  felt-like  mass  of  bacteria  raised 
from  tlie  surface  of  the  enamel ;  c,  a  cavity.    X  12.    (Williams.) 

assured.  Hence,  it  progresses  most  rapidly  when  deep  fissures  of 
molars  have  invited  its  beginnings,  in  deep  pits,  in  approximal  cav- 
ities when  the  tooth-M'alls  are  much  flattened,  and  upon  surfoces 
which  are  partially  overlaid  by  the  soft  tissues  in  such  manner  that 


288  DENTAL  CARIES. 

the  surfaces  are  not  irrigated.  Cases  are  frequently  observed  where 
the  only  external  evidence  of  caries  in  a  molar  or  bicuspid  tooth  is- 
a  blue-black  line  marking  the  fissure,  and  yet  almost  the  entire  dentin 
of  the  crown  may  be  decalcified.  Fig.  245  shows  a  bicuspid  tooth 
from  the  mouth  of  a  woman,  aged  thirty-five  years,  presenting  no 
external  evidence  of  caries,  yet  histological  examination  showed  that 
decalcification  had  proceeded  deeply  into  the  substance  of  the  dentin.'^ 
'•'  There  is  no  doubt  that  many  cases  of  so-called  soft  teeth  have  their 
softness  caused  by  conditions  similar  to  this."  ^ 

While,  as  a  result,  the  extent  of  dentinal  invasion  bears  some  rela- 
tionship to  the  extent  of  enamel-loss,  the  above  examples  are  sufficient 
in  themselves  to  show  that  any  preconceived  opinions  as  to  the  extent 
of  carious  progress  based  upon  the  size  of  the  external  orifice  are 
delusive.  In  point  of  fact,  the  most  extensive  decalcifications  are 
usually  associated  with  limited  enamel-loss  (Fig,  246,  A). 

The  physical  appearance  of  the  carious  cavity  affords  some  indication 
of  the  depth  of  decalcification.  A  cavity  having  slightly  discolored 
ragged  enamel-edges,  but  filled  with  soft  debris,  will  usually  be  found 
to  be  deeply  affected.  On  the  contrary,  cavities  with  broad  mouths, 
but  little  debris,  and  with  discolored  walls,  are  usually  associated  with 
limited  decalcification  (Fig.  246,  B). 

Approximal  cavities  in  bicuspids  and  molars  are  more  likely  to  be 
deep  and  extensive  before  discovery,  than  are  approximal  cavities  in  the 
incisors  :  the  reason  is  obvious. 

While,  as  a  rule,  caries  is  a  regularly  progressive  disease,  going 
deeper  and  deeper  until  all  of  the  tooth-crown  is  destroyed,  conditions 
occur  which  modify  its  progress.     If  the  cavity-walls  be  broken  away 

in  such  manner  as  to  permit  a  free  circulation 
Fig.  246.  of  saliva  in   the  cavity  and  the  tendency  to 

ddbris-accumulation  is  thus  lessened  (Fig.  246, 
B),  the  progress  of  the  disease  may  be  re- 
tarded. In  some  cases,  indeed,  it  is  per- 
manently checked.  The  latter  phenomenon, 
however,  is  rarely  observable  except  in  teeth 
of  a  high  grade  of  organization. 
Again,  caries  may  progress  rapidly  for  a  period,  and  then  receive  a 
check  to  its  progress.  Teeth  previously  free  from  the  disease  may  sud- 
denly fall  victims  to  its  rapid  and  widespread  progress.  No  doubt,  in 
many  of  these  cases  there  are  removed  from  or  added  to  the  local  oral 
conditions  constitutional  influences  which  deter  or  favor  the  local  devel- 
opment of  caries-producing  bacteria. 

While  caries  appears  at  all  ages  from  childhood  to  old  age,  its  rav- 
1  Williams.  '  Black. 


CLINICAL  HISTORY  OF  CARIES.  289 

ages  are  most  pronounced  and  its  progress  most  rapid  during  tlie  period 
of  adolescence  and  early  maturity.  Its  effects  are  most  marked  between 
the  ages  of  eight  and  twenty-five  years.  As  a  rule,  a  denture  which 
remains  for  twenty-five  years  unaffected  by  caries  remains  unaffected 
or  but  slightly  affected  to  an  indefinite  age.  To  be  sure,  this  im- 
plies two  conditions :  first,  that  the  active  causes  of  caries  have 
been  in  but  slight  evidence  ;  and,  secondly,  that  the  denture  is  of  the 
highest  order.  The  classes  of  denture  which  escape  are,  perfectly  formed 
and  symmetrically  arranged  teeth,  in  the  mouths  of  patients  who  lead 
sanitary  lives,  who  masticate  vigorously,  and  who  escape  other  diseases. 
Caries  beginning  at  the  junction  of  the  cemcntum  and  enamel  of 
the  teeth  has  a  somewhat  different  clinical  history  from  that  noted  when 
its  occurrence  is  in  other  situations.  Its  progress  is  subject  to  great 
variations.  In  any  of  the  catarrhal  conditions  or  atrophic  conditions  of 
the  gum  which  lie  bare  the  neck-cementum  caries  usually  occurs.  It 
occurs  also  as  a  process  secondary  to  mechanical  abrasion  and  erosion  of 
the  teeth.  Teeth  afffected  by  erosion,  however,  as  has  been  pointed  out, 
are  commonly  exempt  from  dental  caries. 
19 


CHAPTEE   XIV. 

DENTAL  CARIES :    PATHOLOGY  AND  MORBID  ANATOMY. 

The  pathology  of  dental  caries  deals  with  the  modus  operandi  of 
the  agencies  which  bring  about  the  dissolution  of  the  calcic  tissues  of 
the  teeth.  The  morbid  anatomy  describes  the  changes  of  structure 
which  these  tissues  undergo  in  the  course  of  the  dissolution. 

The  pathology  of  the  disease  varies  according  to  the  method  of  at- 
tack.     If  a  break  or  exposure  in  the  enamel  permits  access  of  the 

Fig.  247. 


Sections  of  normal  human  enamel,  showing  thick,  felt-like  mass  of  micro-organisms  slightly 
raised  from  the  surface  of  the  tissue  by  jjressure  of  the  cover-glass  in  mounting.  X  350. 
(Williams.) 


active  causes  of  caries  to  the  dentin,  the  phenomena  of  dentinal  caries 
begin  at  once ;  if,  however,  the  dentin  is  completely  sheathed  by  un- 
broken enamel,  dissolution  of  the  enamel  must  occur  before  caries  of 
the  dentin  begins.     AVhile  the  essential  nature  of  enamel  and  dentinal 

290 


CARIES  OF  THE  ENAMEL. 


291 


caries  is  nearly  alike,  there  are  distinctive  diiferences  in  the  modes  in 
wliich  their  dissolution  is  brought  about ;  it  should  also  be  noted  that 
caries  of  cementum  exhibits  anatomical  peculiarities. 

Caries  of  the  Enamel. 
For  a  clear  understandino-  of  caries  of  the  enamel  it  is  necessary  to 
recall  the  mode  of  enamel-formation  and  its  composition,  which  were 


Fig.  248. 


Section  of  carious  enamel : 


bacterid  removed  to  show  action  of  acid  on  enamel-rods. 
(Williams.) 


X550. 


discovered  and  set  forth  by  J.  L.  Williams,  who  furnished  also  the  first 

accurate  descri[)tion  of  the  early  and  later  phenomena  of  enamel  caries.^ 

The  enamel  is  composed  of  two  different  substances,  cementing-sub- 

'  It  is  but  just  to  state  in  this  connection  that  Miller's  descriptions  of  the  phenom- 
ena and  pathology  and  morbid  anatomy  of  dental  caries  {Micro-organisms  of  the  Human 
Mouth)  were  as  complete  and  full  as  the  contemporary  knowledge  of  dental  histology 
could  make  them ;  even  more,  his  observations,  correctly  interpreted,  anticipated  some 
of  the  discoveries  of  Williams.  Miller's  descriptions  of  caries  of  the  enamel  given  before 
1S90  would  answer,  with  a  few  modifications,  for  a  description  of  our  present  knowledge 
of  the  subject.  This  in  no  way  belittles  the  work  of  Williams,  which  must  stand  as  a 
permanent  monument  to  his  acumen,  patience,  and  skill  in  histological  technique. 


292 


DENTAL  CARIES. 


stance  and  globules  of  uniform  size,  which  are  built  upon  one  another 
until  rod-like  forms,  the  enamel-prisms,  are  produced.  Each  of  these 
globules  and  each  rod  are  bound  together  by  calcified  cement-substance. 
Acted  upon  by  dilute  acids,  the  cementing-substance  is  seen  to  be  more 
soluble  than  the  globular  bodies. 

"Williams  has  shown  that  felt-like  adherent  masses  of  bacteria  may 
find  lodgement  in  the  remains  of  Nasmyth's  membrane,  in  such  situa- 

FiG.  249. 


Section  of  human  enamel,  approximal  surface  of  incisor,  showing  micro-organisms  of  decay- 
attached  to  the  surface  and  marlced  effect  upon  tissue  caused  by  penetration  of  acid  excreted 
by  the  bacteria.    X  250.    (Williams.) 


tious  as  the  approximal  surfaces  of  the  teeth  (Fig.  247).  "  Lining  the 
cavities  or  covering  the  surface  where  decay  has  commenced  there  is 
always  to  be  seen  a  thick,  felt-like  mass  of  acid-forming  micro-organ- 
isms. This  mass  of  fungi  is  so  dense  and  adhesive  as  to  make  it  highly 
improbable  that  the  enamel  is  affected,  except  in  rare  or  special  instances,  by 
any  acid  other  than  that  which  is  being  excreted  by  the  bacteria  at  the  very 
point  where  they  are  attached  to  the  enamel.     This  thick,  glutinous-like 


CARIES  OF  THE  ENAMEL. 


293 


mass  of  fungi  also  prevents  the  excreted  acid  from  being  washed  away, 
so  that  it  exerts  its  full  chemical  power  upon  calcific  tissue." 

"When  viewed  in  sections,  the  appearances  produced  by  the  action  of 
dilute  lactic  acid  upon  the  enamel  are  similar  whether  the  decalcification 
be  artificial  or  due  to  the  progress  of  caries.  The  cement-substance, 
being  more  soluble  than  the  calcified  globules,  is  dissolved  first,  which 

Fig.  250. 


,^ 


Sectiou  of  human  enamel,  approximal  surface  of  molar,  showing  decay  temporarily  arrested  by  a 
line  of  stratification  ;  micro-organisms  deeply  stained.    X  150.    (Williams.) 


forms  an  irregular,  roughened  surface  at  the  point  of  attack.  The 
gradual  dis.solution  of  the  cement-substance  brings  into  relief  the  struc- 
ture of  the  enamel-rods  (Fig.  248).  The  gradual  loss  of  cement- 
substance  unbinds  the  enamel -globules,  which  are  in  turn  dissolved 
and  washed  away,  leaving  a  depression  or  cavity. 

It  is  common  to  find  in  the  early  stages  of  enamel-caries  and  cavity- 
formation  a  discoloration  of  the  affected  tissue  in  those  cases  where  the 
disease  progresses  very  slowly.     "Whether  this  discoloration  is  caused  by 


294 


DENTAL  CARIES. 


the  formation  of  a  sulfid/  or  is  due  to  the  action  of  chromogenic  bacteria, 
has  not  been  made  out. 

In  Fig.  249  it  is  seen  that  the  advance  of  decalcification  has  brought 
into  bold  relief  the  normal  pigmented  lines  of  the  enamel  (the  strise  of 
Retzius),  with  the  apparent  indication  that  these  lines  offer  territories 
of    increased   resistance   to    decalcification   (see   Erosion).      Lines   of 

Fig.  251. 


Section  of  carious  tooth,  sliowing  appearances  of  decay  in  enamel  and  dentin  at  the  line  of  union 
of  these  tissues  ;  the  dark  spots  shown  in  the  enamel  and  dentin  at  a  and  b  are  masses  of  micro- 
organisms.   X  250.     (Williams.) 


enamel-stratification-  may  temporarily  arrest  the  direct  progress  of 
enamel-dissolution  (Fig.  250).  Decalcification  may  proceed  to  compara- 
tively great  depth  before  cavity-formation  occurs.  In  fact,  the  decal- 
cification may  penetrate  the  entire  thickness  of  the  enamel  and  dentin 
before  there  is  breaking  down  of  the  enamel-walls.  When  the  entire 
thickness  of  the  enamel  is  penetrated  and  the  dentin  attacked  there  is  a 
change  in  the  mode  of  progress  of  the  decalcification.  It  will  be 
recalled  that  the  first  deposited  layers  of  enamel  are  made  in  a  layer  of 
cement-substance  next  to  the  dentin  ;   this  sheet  of  material  appears 

1  Black. 


CARIES  OF  THE  ENAMEL. 


295 


to   offer  less  resistance  to  decalcificatiou    than   other  portions  of  tlie 
enamel. 

If  the  carious  process  begin  in  a  fissure  or  pit,  there  is  little  or 
no  tissue-loss  necessary  before  the  beginning  of  this  secondary  phase  of 
enamelH3aries.  The  solution  of  this  interzonal  layer  of  enamel  occurs 
promptly,  and  decalcification  proceeds  along  the  enamel-rods  from  the 
dentin  side  with  increased  rapidity  (Fig.  251j.     Bacteria  growing  in  the 


Cover-glass  preparation  from  scrapings  of  white,  opaque  decaying  enamel :  the  cement-substance 
between  the  rods  is  seen  to  be  dissolved  away,  and  the  crevasses  thus  formed  are  filled  with 
round  and  oval  forms  of  micrococci  and  bacteria.  Stained  by  the  Gram  method.  >  450. 
(Williams.) 

spaces    from    which    interprismatic    cement-substance    has    disappeared 
cause  detachment  of  masses  of  partially  decalcified  rods  (Fig.  252). 

In  the  ultimate  breaking  down  of  the  enamel  the  rods  first  separate ; 
the  outlines  of  the  several  globules  of  which  the  rods  are  composed  are 
brought  into  plain  view ;  next,  the  calcified  plasmic  strings  noted  in 
enamel-formation  become  evident ;  and  finally  the  bead-like  masses 
upon  these  strings  are  left  as  the  ultimate  granular  detritus  of  the 
enamel. 


296 


DENTAL  CARIES. 


In  cases  of  rapid  enamel-dissolution  Williams  found  streptococci 
almost  invariably  present ;  and  suggests  tentatively  that  the  variety  of 


Fig.  253. 


,-<•■ 


■''V      •.; 


\ 


.^'' 


A  form  of  streptococcus  found  abundantly  in  mouths  where  very  rapid  decay  of  the  teeth  is  in 

progress.    X  V'oO.    (Williams.) 

Fig.  254. 


t  •^- 


>./ 


"~^-  ■   ^'-^ — ' 

Various  forms  of  micrococci  and  bacteria  from  decaying  enamel.    Photographed  hy  Mr.  Andrew 
Pringle  from  Williams'  cover-glass  preparation.    X  1000.    (Williams.) 

organisms  may  be  the  factor  governing  the  rapidity  of  dissolution  (Figs. 


CARIES  OF  THE  ENAMEL. 

Fig.  255. 


297 


Cover-glass  preparation  of  scrapings  from  decay  of  enamel :  shows  leptothrix  buccalis  maxima  and 
bacillus  buccalis  maximus  of  Miller.    Stained  by  Gram  method.  X  850.    (Williams.) 

Fig.  256. 


Scrapings  of  micro-organisms  from  the  approximal  surface  of  a  decaying  tooth  :  shows  the  lepto- 
thrix buccalis  maxima  and  tlie  bacillus  buccalis  maximus  of  Miller,  x  1500.    (Williams.) 


298  DENTAL  CARIES. 

253  and  254).  The  large  cocci  and  diplococci  shown  in  Fig.  252  were 
always  found  in  the  backward  decay  of  enamel. 

"  In  the  direct  caries  of  enamel  the  cavities  are  lined  with  leptothrix 
and  thread-like  forms  "  (Fig.  255). 

""  The  leptothrix  buccalis  maxima  and  the  bacillus  buccalis  maximus 
of  Miller  are  nearly  always  found,  the  latter  more  sparingly"  (Fig.  256). 

"  Beneath  the  felt-like  masses  of  thread-forms  and  lying  in  contact 
with  the  decomposing  enamel  in  direct  decay,  and  also  in  deep  cracks 
and  fissures  in  backward  decay,  there  is  invariably  found  a  short,  thick 
bacillus,  usually  constricted  in  the  centre." 

Caries  of  Dentin. 

Sections  of  carious  dentin  show  the  evidences  of  several  processes — 
chemical,  physiological,  and  pathological — in  operation  at  the  same  time 
(Fig.  257).  First,  the  enamel  is  broken  down  about  a  fissure,  as  shown 
in  the  illustration,  or  is  dissolved  from  a  portion  of  one  of  the  tooth- 
walls  (also  shown).  The  margins  of  the  mouth  of  the  cavity  consist  of 
decalcified  and  discolored  enamel.  Between  the  floor  of  this  cavity  and 
the  pulp-chamber  are  several  distinct  zones,  each  having  a  definite 
pathological  significance.  The  outermost  zones  are  soft  and  discolored, 
but  lying  beyond  them  next  to  the  pulp  is  a  translucent  field,  named, 
from  the  investigator  who  first  called  attention  to  it,  the  transparent 
zone  of  Tomes.  In  the  illustration  it  Avill  be  noted  that  the  trans- 
parent zone  is  continuous  with  the  projection  of  a  secondary  deposit 
upon  a  portion  of  the  pulp-chamber  wall. 

Upon  gross  examination  it  will  be  seen  that  for  some  distance  from 
the  mouth  of  the  cavity  and  in  the  dentin  beneath  the  enamel,  decalcifica- 
tion has  occurred,  and  that  the  formerly  hard  tissue  has  now  but  a  carti- 
laginous density  ;  it  is  soft  to  cutting-instruments.  After  washing  the 
cavity  the  fluid  which  can  be  squeezed  out  of  the  dentin  is  invariably 
acid  in  reaction.  The  more  rapid  destruction  of  dentin  causes  an  under- 
mining of  the  enamel,  which,  being  deprived  of  its  normal  support, 
suffers  more  or  less  fracture  about  its  margins. 

"  Sections  made  of  carious  dentin  parallel  with  the  direction  of  the 
dentinal  tubuli,  and  stained  with  fuchsin,  show  that  the  superficial 
layers  of  the  softened  dentin  are  filled  with  bacterial  forms ;  the  deeper 
layers  of  decalcified  dentin  are  not  infected.  The  decalcification  pre- 
cedes the  invasion  of  the  bacteria  themselves  into  the  dentinal  tubuli."^ 

How  long  the  protoplasmic  processes  in  the  dentin  retain  their 
vitality  when  the  dentin  about  them  has  been  decalcified  has  not 
been  determined.  It  would  appear,  however,  from  clinical  tests  that 
they  do   maintain  their   vitality  for   some  time.     Softened   dentin  is 

1  Miller. 


CARIES  OF  DENTIN. 


299 


often  exquisitely  sensitive  to  touch  ;  \vhether  clue  to  direct  contact  of 
the  instrument  witli  the  dentinal  processes,  or  due  to  the  press- 
ure exerted    being-  transmitted  to    the  vital  processes    beyond,  is  not 


Fig.  257. 


Longitudinal  ground-section  through  the  crown  of  an  inferior  molar  of  the  negro :  E,  enamel ;  D, 
dentin  ;  C,  cement ;  p.  pulp-chamber;  a,  large  decay,  from  the  grinding  surface  ;  b,  small  decay, 
from  the  mesial  surface  ;  cs,  cone  of  septic  invasion  and  discoloration ;  e,  partially  decalcified 
and  discolored  enamel  around  the  carious  cavity;  z,  dark  cones;  z',  clearer  cones  ;  z'p,  oldest 
cones  where  putrefaction  of  the  tooth  cartilage  begins:  c,  outer  transparent  zone, or  zone  of 
Tomes  ;  sd,  secondary  dentin,  caused  by  irritation  ;  s'd'.  secondary  dentin  deposited  by  normal 
physiological  process,  recession  of  the  pulp.  This  figure  is  drawn  from  a  ground  and  polished 
section  mounted  in  Canada  balsam.    (Gysi.) 

known.  Upon  this  point  depends  whether  a  dentin-matrix  which  has 
once  undergone  any  degree  of  decalcification  can  ever  be  the  seat  of 
reconstructive  activity.      Certainly,  in  the  absence  of  live  protoplasm 


300 


DENTAL   CARIES. 


in  it,  softened  dentin  must  remain  soft.  Clinical  records  appear  to 
indicate  that  softened  dentin  has,  after  a  long  period  of  perfect  protec- 
tion, regained  its  hardness.  This  change  can  only  be  brought  about 
through  the  agency  of  the  odontoblastic  processes,  and  very  probably 
cannot  extend  beyond  the  boundaries  of  the  sheaths  of  Neumann. 
Histological  data  are  wanting  in  this  connection. 

It  is  clearly  shown  that  the  primary  ferment  in  dental  caries  per- 
forms one  office :  it  causes  removal  of  the  calcium  salts  of  the  dentin 
in  advance  of  the  organisms.  What  effect  it  may  have  upon  the 
organic  structures  remaining  after  complete  decalcification,  is  question- 
able. It  may  or  may  not  produce  alterations  in  the  gelatinous  matrix 
which  are  a  necessary  preliminary  to  its  future  dissolution.  Subsequent 
to  decalcification  is  the  destruction  of  the  organic  matrix,  which  is 
broken  down  through  the  agency  of  peptonizing  bacteria.  It  will  be 
observed  that  the  peptonizing  ferment  which  causes  this  dissolution  acts 
in  the  presence  of  an  acid. 

The  invasion  of  organisms  takes  place  via  the  dentinal  tubuli.  In 
the  deeper  portions  of  tubules  micrococci  appear  to  predominate  over 

the  rod-forms,  which  are  also  present ;  although 
one  tubule  may  be  filled  with  cocci  and  its 
neighbor  with  rod-forms  (Fig.  258).  It  is 
only  in  the  more  superficial  layers  that  the 
thread-forms  are  found  in  numbers. 

The  invasion  of  the  tubules  is  followed  by 
their  dilatation.  This  change  is  more  plainly 
seen  in  sections  cut  at  right  angles  to  the  axes 
of  the  tubules ;  they  are  distended  to  several 
times  their  usual  size,  until  there  is  an  entire 
disappearance  of  the  intertubular  tissue  (Fig. 
259).  The  walls  of  the  sheaths  of  Neumann 
undergo  thickening,  this  structure  maintaining 


Fig.  258. 


'If  ^ 


Wf^M- 


Fig.  259. 


BS 


#^- 


Decayed  dentin,  showing  a  mixed 
infection  with  cocci  and  bacilli. 
X  400.    (Miller.) 


its  form  to  the  last  stage  of  caries 
appearance  described  by  Tomes. 


Cross-section  of  decayed  dentin  :  the  tubules  through  recip- 
rocal pressure  have  assumed  the  shape  of  5-6  sided 
prisms.    (Miller.) 

and  acquiring  the  tobacco-stem 


CARIES  OF  DENTIN.  301 

Miller  points  out  "  that  the  thickening  of  the  sheath  is  not  a  vital 
process,  since  it  may  be  clearly  observed  in  specimens  of  artificial  decay. 
In  the  progress  of  caries  the  thickened  tubes  dilate ;  a  contraction  of 
the  lumen  is  only  found  when  it  has  occurred  before  softening  began. 

The  tubes  dilate  before  losing  their  identity  as  tubes — i.  e.,  they 
undergo  softening.  Regarding  the  sheaths  of  Neumann  as  transitional 
material,  numerous  data  point  to  the  conclusion  that  the  calcium  salts 
contained  in  them  are  held  in  looser  bonds — i.  e.,  are  more  soluble  than 
the  calcium  salts  impregnating  the  intertubular  dentin. 

It  was  pointed  out  by  Rose^  (see  Chapter  A^III.)  that  what  are 
called  the  transverse  processes  of  the  dentinal  tubuli  react  to  stains  like 
the  sheaths  of  Neumann.  Williams^  has  shown  that  dentin  is  probably 
built  up  of  globular  bodies.  Assuming  that  the  process  of  calcification 
of  dentin  resembles  that  of  enamel,  and  that  both  globules  and  an  inter- 
globular substance  are  deposited  in  a  fibrillated  matrix,  the  appearance 
of  these  transverse  markings  would  be  explained  as  interglobular  sub- 
stance becoming  marked  by  a  partial  decalcification,  and  exhibiting  a 
higher  degree  of  solubility  than  the  globular  bodies.  Rose,^  by  the 
use  of  the  combined  Koch^  and  Golgi  methods  of  staining,  found  that 
these  transverse  branches  of  Neumann's  sheaths  do  not  contain  proto- 
plasmic offshoots  from  odontoblastic  processes ;  they  stain  as  solid 
masses.  Therefore,  the  name  transverse  tubules  is  a  misnomer,  and 
some  explanation  other  than  tubule  penetration  must  be  found  for  the 
invasion  of  micro-organisms  along  these  paths. 

TUBE-CASTS. 

In  the  zone  of  decalcification  in  advance  of  bacterial  invasion  of  the 
tubes  are  found  rod-shaped  bodies,  first  described  by 
J.  Tomes.  They  occur  in  both  natural  and  artificial 
decay ;  hence  it  must  be  inferred  that  their  presence 
is  independent  of  vitality  in  the  dentin — /.  e.,  they 
are  not  caused  by  a  vital  formative  process.  "  The 
rods  do  not  dissolve  in  organic  acids ;  neither  alco- 
hol nor  chloroform  has  any  effect  upon  them  ;  but 
the  addition  of  dilute  sulfuric  acid  causes  their  quick 
dissolution.  In  some  cases  loose  fragments  of  these 
rods  may  be  found  surrounded  by  cocci,  the  rods 
probably  having  been  formed  before  dilatation  of  the  tubes  and  left 
loose  in  the  tubules  by  the  dilatation.  The  rods  are  brittle."  These  fea- 
tures indicated  calcic  formations,  but  the  quantity  of  mineral  was  so  small 
that  the  formation  of  calcium  sulfate  crystals  could  not  be  made  out.^ 

^  Den ta/ Cosmo.?,  1893.  '' Ibi'd.,  1896. 

*  Ibid.  « Ibid.  '=  Miller. 


302  DENTAL  CARIES. 


THE    TEAXSPAEENT    ZONE. 


Far  in  advance  of  the  zone  of  decalcification  the  dentin  acquires  a 
translucent  appearance  resembling  senile  dentin,  and  having  a  similar 
appearance  to  the  dentin  in  some  cases  of  abrasion  and  erosion.  Mil- 
ler's studies  indicate  positively  that  the  translucent  zone  does  not  appear 
in  caries  of  dead  dentin,  in  artificial  caries,  nor  in  caries  of  human  teeth 
mounted  upon  plates. 

Tomes  and  Magitot  both  regarded  the  transparency  as  an  attempt 
made  bv  nature  to  impede  the  progress  of  caries.  Walkhoif  regards  it 
as  evidence  of  stimulation  of  a  formative  activity,  causing  the  production 
of  intercellular  substance  at  the  expense  of  the  cells  and  primarily  their 
offshoots.^  Miller  showed  that  there  is  rather  an  increase  than  diminu- 
tion of  the  calcium  salts  in  the  transparent  zone. 

It  will  be  noted  that  in  Fig.  257  the  transparent  zone  is  continuous 
with  a  new  dentin-formation  upon  the  wall  of  the  pulp-chamber.  These 
evidences  point  to  the  truth  of  WalkhoiF's  explanation  of  the  process, 
and  indicate  that  the  transparent  appearance  is  the  result  of  a  vital  reac- 
tion. The  protoplasmic  processes  of  the  dentin  being  subjected  to  that 
degree  of  stimulation  productive  of  formative  activity,  respond,  and  sec- 
ondary deposits  occur.  While  this  may  be,  and  no  doubt  is,  a  protective 
mechanism  of  nature,  to  assert  that  it  is  a  specific  provision  for  the 
arrest  of  caries  is  perhaps  overstating  the  degree  of  cell-differentiation 
involved.  Clinical  experience  indicates,  however,  that  transparent  den- 
tin does  offer  increased  resistance  to  the  progress  of  caries. 

Cavities  in  which  caries  has  ceased  spontaneously  exhibit  frequently 
the  smooth,  shining  appearance  noted  in  connection  with  mechanical 
abrasion  ;  probably  the  sclerotic  process  noted  above  is  the  cause  of  the 
altered  texture  and  appearance. 

Caries  of  Cementum. 

Decalcification  appears  to  affect  first  the  calcified  rods  known  as 
Sharpey's  fibres ;  the  saprophytic  fungi,  following  these  paths,  invade 
the  cementum  in  a  manner  similar  to  dentin  invasion.  The  bacteria 
invade  the  sites  of  cement-corpuscles  and  their  offshoots. 

Pigmentation  in  Caries. 

In  the  more  slowly  progressing  cases  of  caries  more  or  less  discoloration 
of  dentin  and  surrounding  enamel  occurs.  The  colors  range  from  yellow 
to  jet-black.  "  The  intensity  of  the  discoloration  is-  in  inverse  proportion 
to  the  rapidity  of  the  progress  of  the  disease"  The  discolorations  follow 
upon  and  do  not  precede  the  carious  process.     In  limited,  outlined  areas 

1  Miller. 


CARIES  OF  DEXTIX.  303 

of  enamel  where  the  primary  stage  of  enamel-caries  has  begun,  dis- 
coloration may  occur,  and  the  carious  process  be  checked.  Whether 
there  is  any  connection  between  the  pigmentation  and  the  cessation  of 
caries  is  not  known,  although  in  many  instances  this  would  seem  to  be  the 
case. 

The  chemical  nature  of  these  discolorations  has  not  been  made  out ; 
in  the  cases  of  deep  enamel-staining  they  appear  to  be  due  to  the  deposit 
of  ijrecipitates  upon  the  area  of  decalcification. 

The  discolorations  of  carious  dentin  may  be  due  to  the  action  of 
chromogenic  bacteria.  Miller  isolated  from  the  mouth  an  organism 
which  he  named  bacillus  fuscans,  and  "  which,  cultivated  on  the  surface 
of  nutritive  agar-agar,  imparts  to  the  medium  in  a  few  weeks  a  yellowish- 
brown  color,  which  gradually  darkens  and  extends  deeper  into  the  sub- 
stratum as  the  age  of  the  culture  increases." 

The  discolorations  of  dentin  in  teeth  having  vital  pulps  are  probably 
not  at  all  of  similar  origin  to  the  discolorations  (blue-black)  of  the 
dentin  of  pulpless  teeth. 


CHAPTER   XV. 

DENTAL  CARIES:   DIAGNOSIS,  SYMPTOMS,  AND  PROGNOSIS. 

The  diagnosis  of  dental  caries  is  made  through  objective  signs  and 
subjective  symptoms.  The  signs  are  the  existence  of  cavities  and  of 
softened  areas,  directly  visible  or  made  evident  through  instrumental 
means.  The  symptoms  are  pains  of  several  degrees  of  intensity.  The 
nature  and  intensity  of  the  pains  furnish  a  guide  to  the  depth  of  the 
carious  invasion,  and  but  an  indirect  indication  of  the  location  of  the 
disease. 

Diagnosis  by  Objective  Signs. 

Caries  is  to  be  sought  for  in  those  situations  where  experience,  as 
recorded  in  the  clinical  history  of  the  disease,  teaches  the  operator  to 
examine.  Many  cavities,  particularly  those  of  large  size,  are  evident 
at  first  glance ;  others  require  only  the  light  of  the  mouth-mirror  to 
show  them  plainly,  but  many  require  instrumental  aid  in  the  search. 
The  enamel  of  the  teeth  should  exhibit  a  hard,  smooth,  unbroken 
surface,  and  any  part  of  its  surface  which  will  admit  the  point  of  a 
sharp  exploring-instrument  is  defective,  usually  by  reason  of  the 
jDresence  of  caries.  The  search  for  caries  should  be  made  systemati- 
cally ;  and  to  insure  thoroughness  of  record  every  discovered  cavity 
should  at  the  time  of  examination  be  recorded  upon  a  suitable  diagram. 

Mouth-mirrors  are  required  to  reflect  light  upon  surfaces  of  the 
teeth,  large  ones  being  used  for  this  purpose,  and  smaller  ones  to  reflect 
the  images  of  invisible  tooth -surfaces.  Exploring-instruments  of  vari- 
ous forms  are  used,  having  sharp  points  and  shafts  bent  in  such  manner 
that  all  of  the  surfaces  of  every  tooth  can  be  traversed  by  the  instru- 
ment-points. Floss-silk  is  required  to  pass  between  the  teeth  to  detect 
areas  of  roughness.  Wedging-appliances  are  also  used  to  press  apart 
contiguous  teeth  sufficiently  to  admit  the  exploring-instruments.  A 
general  survey  of  each  tooth  is  made,  aided  by  reflected  light,  and  any 
evident  cavities  are  recorded. 

In  the  absence  of  any  directly  visible  cavities,  an  indication  of  their 
presence  and  depth  may  be  secured  by  having  the  patient  take  a 
mouthful  of  cool — not  cold — water,  and,  closing  the  mouth,  to  distend 
the  cheeks ;  if  there  be  cavities  of  any  depth,  the  presence  of  the  water 
will  usually  cause  pain,  indefinitely  located.     If  pain  be  elicited,  direct 

304 


HYPERSENSITIVITY  OF  DEXTIX.  305 

search  should  be  made  in  the  approximal  spaces  of  the  side  to  Avhich 
the  pain  is  referred. 

In  the  suhsequent  examination  two  systematic  methods  are  pursued. 
In  one  method,  the  occhisal  faces  of  all  the  teeth  are  first  examined  in 
one  survey,  then  the  interproximal  spaces,  and,  lastly,  the  cervices  of 
the  teeth,  and  the  margins  of  fillings,  if  there  be  any.  In  the  other 
method,  every  portion  of  each  tooth  is  examined,  beginning  with  a 
central  incisor  or  terminal  molar,  before  passing  to  the  adjoining  tooth. 
The  first  method  is  more  commonly  followed. 

Fissures  and  pits  in  thti  occlusal,  buccal,  or  labial  surfaces  of  the 
teeth  which  will  admit  and  "  catch  "  the  points  of  fine  exploring-instru- 
ments  are  defective  ;  when  present  in  the  teeth  of  youth  and  young 
adults,  thev  usually  overlie  carious  dentin.  Found  in  the  teeth  of  mid- 
dle-aged patients  they  may  have  little  or  no  clinical  significance.  The 
basilar  pits  of  the  upper  incisors  require  examination  also.  Approximal 
surfaces  are  first  explored  Avith  exploriug-points,  which  detect  the 
presence  of  caries  by  catching  the  margin  of  a  cavity  or  sinking  into 
areas  of  softening.  In  the  absence  of  evident  cavities,  some  force 
should  be  applied  to  detect  soft  spots.  Many  spaces  will  not  admit 
even  fine  exploring-instruments,  in  which  cases  waxed  floss-silk  may  be 
passed  between  the  teeth  and  drawn  backward  and  forward ;  if  it 
"  frays,"  it  indicates  the  existence  of  an  area  requiring  attention.  The 
use  of  wedges,  immediate  or  slow,  may  be  required  for  further  exami- 
nation of  such  spaces.  The  necks  of  the  teeth  should  be  examined  with 
sharp  points  to  note  any  softness  of  the  tooth-tissues.  The  margins, 
particularly  the  cervical  and  neighboring  margins,  of  every  filling 
should  be  explored  to  test  the  integrity  of  the  junction  of  filling 
and  tooth. 

Subjective  Symptoms  of  Caries. 

hypersensitr'ity  of  dentin. 

The  exposure  of  dentin  to  external  agencies  is  so  commonly  followed 
by  an  increase  in  the  normal  sensitivity  that  the  condition  requires 
description  in  itself.  It  is  a  general  condition  attendant  upon  abrasion, 
erosion,  and  caries,  and  has  a  therapeutics  of  its  own. 

The  term  sensitive  dentin  applied  to  this  condition  is  a  misnomer ; 
all  vital  dentin  is  sensitive,  and  its  degree  of  sensitivity  differs  markedly 
in  individuals  ;  it  is  only  when  hypersensitivity  is  observed  that  the 
condition  becomes  pathological. 

Hypersensitivity  of  dentin  may  be  defined  as  such  a  degree  of 
sensitiveness  as  interferes  with  the  proper  excavation  and  shaping 
of  a  carious  cavity  ;  or  which,  in  the  absence  of  dental  ministrations, 
causes  painful  symptoms,  as  a  rule  reflected  about  neighboring  parts. 

20 


306  DENTAL   CARIES. 

Causes. — Normally  the  protoplasmic  filaments  of  the  dentin  are 
completely  protected  from  contact  with  external  sources  of  irritation  by 
the  non-conducting  layer  of  enamel  which  sheaths  the  crown  of  a 
tooth  ;  it  receives  and,  in  all  probability,  notes  stimuli  due  to  changes  in 
the  temperature  of  the  enamel  which  are  induced  by  the  introduction  of 
hot  or  cold  substances  into  the  mouth.  In  general  terms,  the  range  of 
temperature  of  substances  introduced  into  the  mouth  should  be  between 
about  50°  F.,  the  temperature  of  spring  water,  and  105°  F.  or  slightly 
higher,  the  temperature  of  cooked  foods.  It  is  a  common  practice 
among  the  majority  of  persons  to  use  ice  water  at  a  temperature  of  32° 
to  35°  F.,  and  to  have  certain  food-materials  served  very  hot,  at  say 
130°  F.  It  is  evident  that  the  pulps  of  teeth  and  their  terminals, 
the  odontoblastic  processes  in  the  dentin,  subjected  to  these  ab- 
normal stimuli  must  suffer  according  to  the  degree  of  the  frequency 
and  extent  of  the  temperature-change — i.  e.,  the  irritability  of  the 
parts  is  increased. 

It  is  beyond  doubt  that  individuals  differ  as  to  the  degree  of  normal 
dentinal  sensitivity  ;  the  dentin  of  one  person  may  be  cut  freely  without 
evidence  of  marked  pain  ;  in  another,  the  touch  of  an  instrument  to  the 
newly  exposed  dentin  is  productive  of  a  paroxysm  of  pain.  The  differ- 
ence in  degree  of  irritability  is  manifested  in  another  manner  :  if  a  mild 
sedative — for  example,  oil  of  cloves — be  applied  to  the  hypersensitive 
dentin  of  one  person,  it  may  remove  the  distressing  symptoms,  but  with 
others  it  may  be  necessary  to  employ  the  most  extreme  measures  to  re- 
duce in  any  degree  the  hypersensitivity. 

As  soon  as  an  area  of  dentin  loses  its  normal  protective  covering — 
the  enamel,  it  is  subjected  to  altered  conditions,  to  sources  of  irritation 
from  which  it  is  normally  free.  In  the  majority  of  cases  the  exposure 
is  brought  about  by  the  solution  of  overlying  enamel  by  lactic  acid.  In 
others  a  fissure,  a  pit,  or  other  malformation  of  the  enamel  may  lay 
the  dentin  bare ;  or,  as  is  frequently  noted,  the  recession  of  the  gum- 
margin  may  expose  the  thin  layer  of  cementum  covering  the  neck  of  a 
tooth,  and  this  removed  by  abrasion  exposes  the  surface  of  the  dentin 
beneath.  Mechanical  abrasion  of  the  occluding  faces  of  the  teeth  also 
exposes  normally  protected  dentin  to  abnormal  conditions.  Again, 
solution  of  the  enamel  by  the  process  known  as  erosion  exposes  the 
dentin  to  external  sources  of  irritation. 

Pathology  and  Morbid  Anatomy. — While  it  is  true  beyond  ques- 
tion that  the  dentin  is  not,  cannot  be,  the  seat  of  inflammation,  having 
no  vascular  system,  its  vital  parts,  the  so-called  dentinal  fibrillse,  may 
give  evidence  of  heightened  irritability,  and  in  all  probability  behave  as 
any  other  formative  tissue  when  subjected  to  stimulation  and  irritation, 
increasing  the  functional  activity ;  giving  rise,  first,  to  hypersensitivity, 


HYPERSENSITIVITY  OF  DEXTIX.  307 

and  then  to  constructive  action,  or  the  formation  of  dentin  at  the 
expense  of  the  living  portions,  the  tubuli  becoming  more  attenuated. 
Certain  it  is  that  some  molecular  change  must  occur  in  the  vital  parts 
as  the  consequence  of  contact  with  a  novel  environment. 

Symptoms. — The  pain  accompanying  hypersensitivity  of  dentin  is  not 
localized  to  the  point  of  alfection,  for  the  same  reason  that  the  sensations 
of  the  pulp,  except  that  of  throbbing,  are  rarely  localized  ;  the  filaments  do 
not  possess  the  true  tactile  sense,  a  sense  of  location.  The  sensation  of 
pain  is  elicited  by  contact  of  the  dentinal  filaments  with  acid  substances ; 
that  is,  acid  substances  are  markedly  irritating  to  the  dentinal  filaments  ; 
indeed,  it  is  probable  that  this  fact  has  much  to  do  with  the  develop- 
ment of  hypersensitivity  of  dentin,  the  acid  of  caries  (lactic  acid) 
subjecting  these  filaments  to  a  constant  source  of  irritation.  The 
introduction  of  an  acid  substance  into  the  mouth  of  a  person  who 
may  have  vital  dentin  exposed,  is  followed  by  a  wave  of  gnawing  pain, 
reflected  usually  along  the  course  of  contiguous  nerve-filaments.  The 
introduction  of  salt  and  very  sweet  substances  is  also  followed  by  a 
similar  though  less  marked  reaction.  The  pressure  of  an  instrument 
upon  the  dentin  is  attended  by  a  flash  of  sharp  pain,  which  continues 
for  a  time  ;  but  lessens  if  the  contact  be  maintained.  In  this  test  the 
pain  is  localized  in  the  affected  tooth,  the  touch  of  the  instrument  being 
followed  by  a  recognition  of  position  by  the  tactile  organ  of  the  tooth, 
the  pericementum.  The  response  of  such  teeth  to  thermal  applications 
is  increased,  the  absence  of  the  non-conducting  layer  of  enamel  permit- 
ting a  more  rapid  reduction  of  dentinal  temperature,  so  that  the  reaction 
of  the  pulp  is  correspondingly  increased. 

Diag-nosis. — The  only  dental  pain  with  which  dental  hypersensitivity 
may  be  confounded  is  pulp-pain  proper.  The  diagnostic  feature  of 
pulp-pain  is  the  reaction  to  changes  of  temperature.  It  is  quite  possible 
for  marked  pulp-irritation,  followed  by  active  hypersemia  of  that  organ, 
to  occur  without  the  presence  of  caries  in  a  tooth.  In  diagnosing  the 
condition  under  discussion  the  guide  is  the  sensation  of  the  patient, 
search  being  first  made  in  the  region  descril)ed  by  the  patient  as  the 
seat  of  pain.  The  first  observation  is  directed  to  the  finding  of  carious 
cavities ;  in  the  event  of  these  being  found,  it  is  judged  from  the  depth 
of  the  carious  invasion  whether  there  is  a  probability  of  pulp-disturb- 
ance. A  differential  test  is  made  by  contact  of  an  instrument  with  the 
dentin,  which,  if  hypersensitive,  responds  promptly.  A  drop  of  cool 
water  is  next  dropped  from  a  syringe  into  the  cavity,  when,  if  the 
pulp  be  in  abnormal  condition,  there  will  be  a  sharp  twinge  of 
])ain.  In  progressive  caries  this  latter  response  is  of  increasing 
promptness  and  severity,  until  when  the  pulp  is  in  a  state  of  active 
hypersemia  or  inflammation  the  application   of  a  drop  of  cold  water 


308  DENTAL  CARIES. 

is  immediately  followed  by  a  paroxysm  of  throbbing  pain.  Obser- 
vation is  made  to  determine  the  presence  of  abraded  surfaces  ex- 
posing the  dentin,  and  test  by  touch  made.  It  is  next  noted  whether 
points  at  the  necks  of  the  teeth  respond  promptly  to  the  same  test. 
Attention  is  directed  to  fissures  and  pits  which  may  be  present  and 
expose  the  dentin. 

Hypersemia  of  the  pulp,  in  the  absence  of  caries,  is  indicated  by  a 
sharp  paroxysm  of  pain  produced  by  the  application  of  cold  to  the 
enamel  of  the  tooth. 

Therapeutics. — The  methods  of  treatment  which  have  been  followed 
for  the  relief  of  hypersensitivity  of  dentin,  and  the  induction  of  such  a 
degree  of  analgesia  as  will  permit  the  necessary  cutting  of  dentin,  may 
be  divided  into  general  and  local. 

The  general  means  of  preventing  pain  may  be  placed  under  three 
heads  :  first,  the  administration  of  agents  which  lessen  the  function  of 
the  pain-perceptive  centres  of  the  brain — that  is,  abolish  perception ; 
secondly,  the  administration  of  remedies  or  the  adoption  of  means  to 
prevent  the  conveyance  of  painful  impressions  from  the  receptive  end- 
organs  to  the  pain-centres,  or  interference  with  transmission  ;  thirdly, 
the  prevention  of  the  reception  of  abnormal  stimuli. 

The  first  group  includes  general  ansesthetics  and  general  anodynes. 
The  inhalation  of  a  few  whiifs  of  chloroform  or  ethylic  ether  lessens 
the  perception  of  pain.  Chloroform  is  avoided  in  this  connection  on 
account  of  its  dangers  when  used  in  the  sitting  position.  Slight  etheriz- 
ation, the  inhalation  being  carried  only  to  the  benumbing-point,  affords 
marked  relief  of  the  pain  incidental  to  the  cutting  of  hypersensitive 
dentin. 

The  administration  of  general  anodynes,  particularly  the  combina- 
tion of  morphia  and  atropia,  has  been  found  useful  in  this  field : 

^.  Morphise  sulph.,  gr.  ^  ; 

Atropise  sulph.,  gr.  y^Q-. 

M.  et  ft.  pil.  No.  1. 
S.  To  be  taken  one-half  hour  before  operation. 

The  coal-tar  derivatives,  phenacetin,  acetanilid,  and  others,  are  occa- 
sionally efficient.  The  preparations  known  as  antikamnia  (said  to  be  a 
combination  of  acetanilid,  caflTein  citrate,  and  sodium  bicarbonate)  and 
ammonol  (acetanilid  and  ammonium  carbonate,  equal  parts  ?)  are  to  be 
preferred  in  this  connection.  The  dose  of  the  latter  is  gr.  10,  adminis- 
tered one-half  hour  before  operation. 

The  induction  of  the  hypnotic  state  belongs  in  the  category  of  means 
acting  upon  the  nerve-centres. 


HYPERSENSITIVITY  OF  DENTIN.  309 

Use  of  Alkalies. — Ever  since  a  belief  in  the  chemical  nature  of 
dental  caries  has  been  accepted,  writers  upon  dental  pathology  have 
ascribed  the  hypersensitivity  of  dentin  in  caries  to  be  due  to  the  action 
of  an  acid,  and  have  advised  the  use  of  alkalies  to  lessen  the  sensitivity. 
Those  generally  recommended  are  lime-water,  prepared  chalk,  and 
sodium  bicarbonate.  These  agents  are  commonly  employed  in  cases  of 
hypersensitive  dentin  at  the  necks  of  teeth ;  the  powder  is  rubbed  on 
and  between  the  necks  of  the  teeth  before  retiring  at  night.  An  effective 
agent  of  the  same  class  is  phenol  sodique  (sodium  phenate).  Used 
(diluted)  as  a  frequent  wash,  it  notably  lessens  the  sensitivity  of  den- 
tinal filaments.     It  is  particularly  useful  for  children. 

Local  Applications. — The  usual  method  of  treating  the  hyper- 
sensitivity is  by  the  local  application  of  analgesic  agents.  There  are 
numerous  remedies  and  agents  which  have  been  thus  employed,  and  for 
convenience  they  may  be  grouped  under  the  following  headings  : 

1.  Dryness  and  heat. 

2.  Cold. 

3.  Those  which  chemically  destroy  the  protoplasm  of  the  dentin. 

4.  Those  which  temporarily  benumb  and  abolish  the  function  of  the 
receptive  apparatus. 

Heat  and  dryness  are  generally  applied  in  conjunction,  dryness  being 
secured  by  means  of  blasts  of  hot  air.  Dentin,  which  protests  against 
even  the  touch  of  an  instrument  while  wet,  has  its  sensitivity  so  lessened 
after  the  application  of  a  rubber-dam  and  drying  that  it  may  be  cut 
freely,  in  many  cases  without  the  aid  of  medicinal  agents.  So  well  is 
this  recognized  that  isolation  and  drying  of  teeth  are  regarded  as  a 
necessary  preliminary  to  cavity-preparation.  The  degree  of  insensi- 
tivity  induced  is  in  proportion  to  the  dryness.  The  drying  probably 
deprives  the  dentinal  protoplasm  of  a  portion  of  its  water  and  inhibits 
the  transmission  of  sensation. 

Refrigeration,  a  well-knoM'n  means  of  inducing  local  anaesthesia, 
finds  application  in  this  field.  The  temperature  of  the  dentin  of  the 
tooth,  which  has  been  isolated  by  a  rubber-dam,  is  reduced  by  sprays  of 
highly  volatile  fluids  ;  ether  and  chloroform,  formerly  employed,  have 
been  displaced  by  the  more  volatile  substances,  ethyl  chlorid  and  methyl 
chlorid.  These  agents  are  contained  in  glass  tubes  having  a  minute  ori- 
fice of  exit ;  the  cap  of  the  vial  being  removed,  the  heat  of  the  hand 
causes  vaporization  of  the  agent,  which  emerges  as  a  fine  but  forcible 
spray.  The  full  contact  of  the  spray  with  the  dentin  should  be  made 
gradually  to  avoid  painful  response  of  the  pulp. 

Agents  which  chemically  destroy  the  dentinal  protoplasm  form  the 
most  extensive  group  of  dentinal  obtundents.  They  include  salts  of 
metals,  such  as  zinc  chlorid  and  silver  nitrate ;  carbolic  acid  and  its 


310  DENTAL  CARIES. 

derivatives  and  like  bodies ;  the  cresols,  etc. ;  mineral  acids,  notably 
sulfuric,  chromic,  and  nitric ;  organic  acids — trichloracetic  and  lactic 
acids  (full  strength),  tannic  acid ;  alkalies — sodium  and  potassium 
hydrates  and  carbonates. 

Zinc  chlorid,  silver  nitrate,  and  carbolic  acid,  all  cause  coagulation 
of  the  protoplasmic  processes  of  the  dentin.  The  mineral  and  organic 
acids  chemically  decompose  both  protoplasm  and  the  calcified  tissues. 
The  concentrated  alkalies  mentioned  chemically  destroy  protoplasm 
and  bring  about  its  quick  dissolution.  Like  all  active  chemical  sub- 
stances, the  extent  of  their  action  depends  upon  the  freedom  with  which 
they  are  applied. 

The  caustic  alkalies  are  used  in  connection  with  carbolic  acid 
(Robinson's  remedy) : 

!^.  Potassium  hydrate  or^ 

Sodium  hydrate,  >  da. — M. 

Acid,  carbolic,  J 

Reduce  the  gelatinous  mass  formed  with  alcohol. 

The  application  of  any  of  these  agents — metallic  salts  (coagulants), 
mineral  or  organic  acids,  and  caustic  alkalies — nearly  always  causes 
pain,  the  degree  of  suffering  being  usually  in  proportion  to  the  depth 
of  the  cavity.  The  cessation  of  the  pain  is  an  indication  of  proto- 
plasmic destruction.  All  of  these  agents  are  to  be  used  in  small 
amount  and  very  concentrated ;  dilute  solutions  are  ineffective.  Car- 
bolic acid  and  allied  substances  have  an  analgesic,  instead  of  the  primary 
irritating  effect.  They  are  paralyzants  as  well  as  coagulants,  although 
less  active  than  the  other  agents  mentioned.  Arsenic  trioxid,  arsenious 
acid,  the  agent  used  for  the  purpose  of  devitalizing  the  dental  pulp, 
affects  the  protoplasm  of  the  dentin  profoundly,  the  effect  being  trans- 
mitted to  the  pulp,  leading  to  the  inevitable  death  of  that  organ. 

The  local  analgesics  proper  include  the  essential  oils  and  the  sedative 
alkaloids ;  the  oils  of  cinnamon,  cloves,  gaultheria,  thyme.  These 
exhibit  the  best  effects  in  close  proximity  to  the  pulp.  Thymol  is  the 
most  powerful  member  of  this  group,  and  in  addition  is  a  strong  anti- 
septic. The  alkaloids  Avhich  have  been  used  are  morphia,  atropia, 
veratria,  aconitia,  and  cocain.  To  be  at  all  effective,  these  alkaloids 
must  be  used  in  concentrated  form,  so  that  the  possible  danger  of 
poisoning  by  such  powerfully  toxic  substances  as  aconitia,  veratria,  and 
atropia,  contraindicates  their  general  use  ;  moreover,  they  are  unneces- 
sary. Morphia  is  ineffective.  Cocain,  the  chief  of  all  local  anaesthetics, 
has  but  little  effect  upon  hypersensitive  dentinal  filaments,  although 
made  into  paste  with  glycerin  it  appears  to  be  effective  in  some  cases. 


HYPERSENSITIVITY  OF  DENTIN.  311 

Absorption  of  the  drug  by  the  dentinal  filaments  does  not  occur,  so  that 
supplementary  means  are  necessary  to  carry  it  into  the  filaments.  This 
is  accomplished  through  the  agency  of  a  galvanic  current. 

The  tooth-pulp  is  excessively  intolerant  of  changes  of  electric 
tension.  If  a  tooth  be  perfectly  isolated  from  its  surroundings  by 
means  of  a  rubber-dam,  and  a  very  mild  galvanic  current  be  passed 
through  the  tooth,  the  positive  electrode  in  the  tooth-cavity,  and 
the  negative  attached  to  the  Avrist  or  elsewhere,  the  pulp  will  respond 
promptly.  If  the  current  be  continued,  the  response  lessens,  and  finally 
ceases.  Now,  if  the  tension  be  iucreased  by  a  considerable  fraction  of 
a  volt,  the  pulp  again  protests  ;  but  if  the  increase  be  only  a  minute 
fraction  of  a  volt,  the  pulp  does  not  take  cognizance  of  it ;  the  voltage 
may  thus,  by  imperceptible  gradations,  be  raised  from  five  volts  to  forty. 
The  amount  of  electrical  resistance  offered  by  the  tissues  being  extremely 
high,  but  a  trifling  amperage  of  current  can  pass  through  the  tooth, 
even  with  forty  volts  pressure.  If  the  dentin  become  dry,  the  resist- 
ance is  much  increased,  as  the  only  conducting-paths  through  the  dentin 
are  the  dentinal  tubuli  when  wet.  Apparatus  has  been  devised  which 
permits  the  raising  of  current-tension  by  minute  gradations,  Avhich 
has  rendered  available  the  cataphoretic  use  of  medicaments  in  vital 
teeth. 

Cataphoresis  (Greek  hata,  down,  and  phoreo,  I  bear  or  bring)  is, 
in  technical  parlance,  the  transfereuce  of  substances  from  the  anodal  or 
positive  pole  of  a  battery  toward  the  cathodal  or  negative  pole.  Cata- 
phoresis, is  to  be  distinguished  from  electrolysis,  by  which  substances  are 
decomposed  and  their  elements  carried  from  positive  to  negative,  or 
from  negative  to  positive  poles,  according  to  their  polarity.  In  cata- 
phoresis a  substance  is  carried  unchanged  from  the  positive  toward  the 
negative  pole  after  the  manner  of  granules  in  protoplasm  acted  upon  by 
the  same  force  (see  Chapter  I.).  If  a  tooth  be  insulated  from  its 
surroundings  and  a  pellet  of  cotton  moistened  with  a  strong  (10  per 
cent,  to  24  per  cent.)  solution  of  cocain  hydrochlorid  and  a  platinum 
anode  be  placed  against  it,  the  cathode  being  attached  to  the  wrist,  the 
cocain  will,  by  a  current  of  gradually  increasing  tension,  be  carried 
along  the  protoplasm  of  the  dentinal  tubuli  and  induce  local  paralysis 
of  the  sensory  function.  If  the  action  be  continued  with  an  increased 
voltage,  the  entire  pulp  becomes  completely  anesthetic.  The  volume  of 
current  necessary  to  the  cataphoresis  of  the  cocain  ranges  from  one- 
quarter  to  four  milliamperes.^  The  current-strength  required  ranges  from 
five  to  thirty  volts.  Caution  must  be  exercised  to  keep  the  cotton  always 
wet,  as  dryness  means  greatly  increased  resistance  and  heat.  The  time 
necessary  for  the  induction  of  dentinal  anaesthesia  ranges  from  about 
^  See  American  Text-book  of  Operative  Dentistry, 


312  DENTAL  CARIES. 

eight  to  twenty  minutes.  J.  A.  Woodward  ^  suggests  the  use  of  the 
galvanic  current  as  a  diagnostic  means  of  determining  the  vitality  of  a 
pulp.  A  pulpless  tooth  does  not  respond  when  currents  of  comparatively 
high  tension  are  passed  through  it. 

It  is  customary  to  test  the  milder  obtundents  before  resorting  to 
cataphoresis. 

Certain  general  rules  should  be  observed  in  the  treatment  of  hyper- 
sensitive dentin  : 

First.  The  most  powerful  agents,  such  as  mineral  acids,  zinc  chlorid, 
concentrated  alkalies,  etc.,  should  never  be  used  except  in  superficial 
cavities.  With  increase  of  cavity-depth  milder  agents  may  be  sub- 
stituted, until,  when  the  pulp  is  nearly  exposed,  no  more  active  agent 
than  thymol  should  be  employed. 

Second.  Resort  should  not  be  had  to  the  active  chemical  agents  until 
milder  agents  have  proved  inefficient.  For  example,  zinc  chlorid  or 
sulfuric  acid  should  never  be  the  first  agent  used. 

Third.  All  cavities  should  be  isolated  and  dried  before  using  obtund- 
ing  agents. 

Fourth.  Arsenic  should  never  be  used  unless  destruction  of  the  pulp 
is  intended. 

Fifth.  None  but  new  and  perfectly  sharpened  instruments  should  be 
used  to  cut  hypersensitive  dentin,  and  the  cutting  should  be  accomplished 
with  quick,  light  touches. 

Prognosis  of  Caries. 

The  prognosis  of  dental  caries  is  governed  almost  entirely  by  the 
thoroughness  with  which  the  indicated  therapeusis  is  applied.  In  the 
absence  of  treatment,  the  disease,  except  in  very  rare  cases,  is  con- 
tinuously progressive  until  the  greater  portion  of  the  tooth  is  dis- 
integrated. Under  proper  and  sufficient  treatment  the  disease  may  be 
arrested  at  any  stage  of  its  progress,  in  any  individual  tooth ;  but  the 
arrest  of  the  process  in  toto  can  only  be  secured  by  a  removal  of  its 
causes,  both  exciting  and  predisposing.  If  the  exciting  causes  can  be 
checked  or  removed,  the  predisposing  causes  will  be  in  abeyance. 
Caries  will  persist  or  recur  so  long  as  the  exciting  causes  of  the  disease 
are  present. 

^  Proc.  Academy  of  Stomatology,  Phila.,  1896. 


CHAPTER   XVI 


Fro.  261. 


f)ENTAL  CARIES:   THERAPEUTICS  AND  PROPHYLAXIS. 

It  is  customary  to  divide  the  course  of  caries  into  a  number  of 
degrees  or  stages,  each  of  which  represents  a  more  or  less  definite 
extent  of  invasion  in  the  direction  of  the  pulp,  and  in  each  of  which 
the  indicated  therapeusis  must  be  modified  in  accordance  with  the  con- 
ditions. The  first  stage  or  grade,  called 
superficial  caries,  represents  the  lesser 
degrees  of  softening  and  invasion  of  den- 
tin, those  cases  in  which  as  yet  no  evi- 
dences of  any  disturbance  of  the  pulp 
have  appeared.  The  second  degree  or  stage 
is  that  in  which  pulp-protection  forms  a 
necessary  part  of  the  treatment.  The 
third  stage  is  that  in  which  the  depth  of 
infection  has  endangered  the  functions  or 
structure  of  the  pulp.  The  fourth  stage 
includes  the  cases  of  either  actual  invasion 
of  the  pulp  by  micro-organisms,  or  those 

which  exhibit  evidences  of  fiital  structural  changes  in  the  vessels  of 
the  pulp. 

The  general  therapeutic  principle  in  the  treatment  of  dental  caries  is 
the  removal  of  all  softened  and  infected  tissue  and  the  restoration  of 
the  original  tooth-form  by  means  of  filling-materials.  This  general 
therapeutic  principle  is  modified  according  to  the  depth  of  carious  inva- 
sion— i.  e.,  the  condition  of  the  tissues  involved. 


figures  reprLbcnt  the  four  degrees 
of  carious  invasion. 


Filling-materials  as  Therapeutic  Agents. 

Regarding  as  therapeutic  agents  all  materials  which  by  their  physical 
or  chemical  properties  affect  the  vital  processes  of  tissues  with  which 
they  may  be  brought  into  contact,  it  is  evident  that  filling-materials 
themselves  must  be  classed  as  therapeutic  agents. 

The  theoretically  perfect  filling-material  is  one  which  possesses  all 
of  the  physical  properties  of  dentin  and  enamel,  but  is  not,  like  these 
substances,  soluble  in  lactic  acid.  The  first  essential  of  a  permanent 
filling-material  is,  that  it  must  hermetically  seal  a  cavity  in  which  it  is 
placed,  and  undergo  no  physical  or  chemical  change  which  may  bring 

313 


314  DENTAL  CARIES. 

about  a  failure  of  the  hermetical  sealing ;  that  is,  it  must  neither  con- 
tract nor  expand,  and  must  be  insoluble  in  organic  acids,  the  solvents 
formed  in  the  human  mouth.  It  must  be  sufficiently  hard  and  rigid  to 
remain  unaffected  by  the  stress  brought  to  bear  upon  it  in  mastication. 
It  must  be  susceptible  of  a  high  polish,  possess  a  harmonious  color,  and 
have  a  low  rate  of  thermal  conductivity.  Not  one  of  the  filling- 
materials  in  present  use  possesses,  in  itself,  all  of  these  properties, 
although  combinations  of  them,  by  adding  together  the  individual 
virtues  of  single  materials,  remove  several  deficiencies  of  individual 
materials. 

Gold,  skilfully  manipulated,  may  be  made  to  hermetically  seal  a 
cavity.  It  remains  chemically  and  physically  unaltered  in  the  condi- 
tions surrounding  it ;  properly  inserted,  it  withstands  the  stress  of 
mastication,  and  is  susceptible  of  a  high  polish,  but  its  rate  of  conduc- 
tivity is  high,  and  its  color  is  objectionable,  although  less  so  than  that 
of  amalgam. 

Amalgams,  as  found  commercially,  expand  or  contract  in  setting  or 
hardening,  so  that  they  do  not  permanently  seal  in  their  hardened  state 
a  cavity  which  they  exactly  filled  while  plastic.  Under  the  stress  of 
mastication  amalgam  flows,  so  that  changes  in  the  shape  of  a  filling 
occur.  They  are  insoluble  in  the  organic  acids  of  the  mouth,  but  are 
acted  upon  by  sulfur  compounds  and  probably  by  oxygen,  so  that  their 
color,  primarily  not  so  harmonious  as  that  of  gold,  becomes  more  objec- 
tionable. They  have  a  lower  rate  of  conductivity  than  gold.  By 
precise  formulae,  properly  treated^  they  may  be  made  to  remain  stable 
as  to  contraction  and  expansion ;  but  except  copper  be  added  to  the 
alloy,  the  flow  of  amalgam-fillings  cannot  be  entirely  checked,  in 
which  event  discolorations  are  more  likely.  Color  may  be  improved  by 
the  addition  of  zinc  and  gold  to  a  basal  alloy  of  silver  and  tin.  To 
insure  stability  of  an  amalgam-filling  the  primary  alloy  must  contain 
not  less  than  65  per  cent,  of  silver.^  The  value  of  all  filling-materials 
depends  primarily  upon  the  skill  and  care  with  which  they  are  manip- 
ulated. 

It  is  still  asserted  by  some  homoeopathic  practitioners  that  amalgam- 
fillings,  in  consequence  of  the  free  mercury  contained  in  them,  are 
instrumental  in  perpetuating  diseases  of  the  buccal  and  pharyngeal 
mucous  membrane,  and  that  obscure  general  disturbances  are  also  due 
to  this  cause.  A  hardened  amalgam-filling  contains  no  free  mercury  ; 
all  of  this  metal  present  is  in  chemicial  combination  with  the  metals  of 
the  alloy.  Metallic  mercury  is  unaffected  at  ordinary  temperatures  by 
any  chemical  agencies  found  in  the  mouth,  with  the  exception  of  sulfur 

^  See  American  Text-hook  of  Operative  Dentistry. 
^  Black,  Dental  Cosmos,  1896. 


THERAPEUTICS  OF  SUPERFICIAL  CARIES.  315 

coinpuiinds  ;  the  statement  that  it  is  the  "  vapor  of  mercury  "  is  absurd  ; 
mercury  vaporizes  only  at  a  temperature  of  over  600°  F. 

Amalgam-fillino;s  in  contact  with  dentin  in  which  putrefaction  is  in 
progress  are  frequently  discolored  by  the  formation  of  presumably  black 
sulfid  of  silver  and  perhaps  salts  of  mercury,  the  dentin  being  stained 
black. 

Gutta-percha  possesses  the  advantageous  properties  of  entire  non- 
conductivity,  an  agreeable  color,  comparative  unchangeability  in  the 
fluids  of  the  mouth,  and  hermetical  sealing,  but  it  is  too  soft  to  resist" 
attrition  and  the  stress  of  mastication. 

Zinc  oxychlorid  in  paste  (ZnO  +  ZnCl^  +  H^O  =  2ZnClHO)  is 
irritating  to  the  dentinal  filaments,  the  promptness  of  painful  response 
being  directly  proportionate  to  the  cavity-depth  ;  it  is  antiseptic  during 
setting  and  for  some  time  subsequently  ;  it  is  a  non-conductor,  is  white, 
and  when  fully  set  is  not  sufficiently  hard  to  bear  the  stress  of  mastica- 
tion ;  its  great  drawback  is  its  ready  solubility  in  lactic  acid.  More- 
over, it  shrinks  in  hardening. 

Zinc  phosphate  has  an  acceptable  color ;  its  rate  of  conductivity  is 
higher  than  that  of  zinc  oxychlorid ;  it  does  not  contract  in  hardening, 
and  is  adhesive  ;  but  its  hardness  is  not  sufficient  to  permanently  resist  the 
stress  of  mastication,  and  it  is  also  soluble  in  lactic  acid,  although  less 
so  than  zinc  oxychlorid.  The  properties  of  zinc-phosphate  cements  are 
governed  by  the  chemical  composition  of  particular  specimens  and  in 
large  part  by  their  mode  of  manipulation. 

Therapeutics  of  Superficial  Caries. 

The  therapeutics  of  the  first  stage  or  superficial  dental  caries  consists 
in  the  thorough  removal  of  all  softened  tissue,  including  all  enamel 
which  has  suffered  from  the  action  of  lactic  acid  and  all  dentin  which 
has  become  secondarily  affected. 

In  cases  of  enamel  caries,  affecting  the  approximal  surfaces  of  teeth, 
the  practice  has  been  advocated  of  filing  away  the  affected  enamel, 
when  evident  softening  has  not  penetrated  the  entire  thickness  of  the 
enamel,  and  polishing  the  cut  surface,  leaving,  if  possible,  a  space  so 
shaped  that  the  fluids  of  the  mouth  can  wash  freelj^  through.  Were  it 
certain  that  all  of  the  decalcified  enamel  could  be  removed  by  such 
means,  and  after  operation  a  perfectly  polished  and  properly  shaped 
surface  of  unaffected  enamel  be  left,  no  valid  objection  could  be  urged 
against  the  judicious  following  of  the  method ;  but,  as  Williams'  ^ 
studies  have  shown,  the  advance  of  enamel  caries  is  usually  far  in 
advance  of  the  visible  evidences  of  the  decalcification  ;  the  practice  of 
filing   leaves   practically  unchanged   the   pathological    conditions,  and 

^  Dental  Cosmos,  1897. 


316  DENTAL  GABIES. 

further  progress  of  enamel  decalcification  at  the  original  site  is  very 
likely  to  occur.  In  the  light  of  the  same  discoveries,  the  prudent 
therapeusis  is  to  excavate  such  spots  of  softening  to  the  extreme  margin 
of  the  softening.  Whether  or  not  the  dentin  is  as  yet  affected,  the 
excavation  must  be  continued  until  sufficient  dentin  is  invaded  by  the 
cutting-instruments  to  afford  firm  anchorage  and  support  of  the  filling 
which  is  to  restore  the  original  contour.  It  will  be  observed  that  the 
physical  and  chemical  properties  of  gold  indicate  it  as  the  proper  filling- 
material  in  these  cases. 

In  similar  cases  at  a  later  stage,  when  the  dentin  is  invaded,  the 
softened  dentin  is  to  be  entirely  removed,  and  with  it  all  of  the  enamel 
overlying  such  dentin,  until  the  cavity  formed  is  bounded  upon  all  sides 
by  normal  dentin  and  enamel.  The  removal  of  all  softened  dentin 
renders  unnecessary  the  use  of  gemicides  to  the  dentin,  as  softening  is 
in  advance  of  infection.  In  case  of  dentinal  hypersensitivity  in  these 
cases  it  is  usual  to  apply  carbolic  acid  as  the  first  obtunding  agent ;  in 
which  event,  the  same  agent  answers  as  a  germicide  also,  but,  as  above 
noted,  germicides  are  unnecessary  in  this  stage,  if  excavation  be  thorough. 
In  some  cases,  particularly  those  in  which  it  is  necessary  to  apply  zinc 
chlorid,  or  even  sulfuric  acid,  to  obtund  the  hypersensitivity  of  the 
dentin,  or  cases  in  which  the  cataphoretic  application  of  cocain  must  be 
made,  the  prepared  dentin  may  become  inordinately  sensitive  ;  moreover, 
the  pulp  responds  with  dangerous  promptitude  to  changes  of  tempera- 
ture. It  is  frequently  advisable  in  these  cases  to  treat  the  dentin  as  a 
wounded  surface  :  procure  surgical  rest  for  a  period  ;  after  touching  the 
cavity-walls  with  one  of  the  obtundent  oils,  insert  a  perfectly  neutral 
and  non-conducting  filling-material — gutta-percha — for  a  period  of  some 
weeks.  The  alternative  is  to  apply  carbolic  acid  to  the  dentinal  walls, 
dry  perfectly,  and  coat  the  cavity-walls  with  a  non-conducting  varnish, 
such  as  that  called  Kristalline,  or  Cavitine,  a  solution  of  tri-nitro-cellu- 
lose  in  methyl  alcohol.  When  evaporation  has  left  a  non-conducting 
film  covering  the  cavity-walls  a  gold  filling  may  be  inserted. 

A  tooth  in  which  thermal  response  is  markedly  increased  through 
the  presence  of  metallic  fillings,  is  always  to  be  regarded  as  one  whose 
pulp  is  in  danger  of  future  disease  and  degeneration.  The  presence  of 
a  metallic  filling  in  a  tooth  is  almost  certain  to  increase  thermal  response 
in  some  degree,  but  the  extent  and  promptness  should  be  reduced 
through  the  use  of  an  intermediate  non-conductor. 

Superficial  caries  beginning  in  fissures  or  pits  of  the  enamel  is  fre- 
quently of  much  greater  extent  than  is  evident  from  the  orifice  of  the 
cavity.  If  the  seat  be  a  fissure,  this  should  always  be  freely  and  broadly 
opened  from  one  extremity  to  the  other,  and  usually  it  is  necessary  to 
cut  into  communicating  fissures.     The  excavating  instruments  should 


THERAPEUTICS  OF  THE  SECOND  STAGE  OF  CARIES.         317 

follow  every  spot  of  softening  until  it  is  certain  sound  dentin  has  been 
reached  in  all  directions,  and,  in  addition,  the  enamel  must  be  cut  away 
until  it  is  supported  at  all  of  the  cavity-margins  by  healthy  dentin. 
Cavities  beginning  in  fissures  are  very  deceptive  as  to  their  extent ;  a 
slight  fissure  may  communicate  with  such  a  mass  of  softened  dentin  that 
the  case  belongs  in  the  second  class  of  cavities — deep-seated  instead  of 
superficial  caries. 

Therapeutics  of  the  Second  Stage  of  Caries. 

In  this  stage  of  caries  there  is  usually,  although  by  no  means  always, 
an  easily  discoverable  cavity  of  size.  After  the  removal  of  ragged  and 
overhanging  enamel-margins,  and  of  loose  debris  in  the  cavity,  it  is 
noted  that  the  response  to  thermal  impulse  is  painful  and  prompt.  In 
washing  such  cavities,  water  at  a  temperature  of  about  100°  F.  should 
always  be  used ;  cold  or  very  hot  water  being  only  employed  in  cavity- 
irrigation  to  test  the  promptitude  of  response  upon  the  part  of  the  pulp. 

In  treating  hypersensitivity  of  dentin  in  such  cases  the  strong  agents 
zinc  chlorid  and  the  mineral  acids  are  eschewed,  the  strongest  agent 
admissible  being  carbolic  acid,  and  even  the  use  of  this  agent,  acting  as 
it  does  as  a  coagulant,  is  of  doubtful  propriety.  A  perfectly  safe  thera- 
peusis  does  not  admit  of  a  stronger  agent  than  an  essential  oil ;  for 
example,  a  saturated  solution  of  thymol  in  glycerin  or  alcohol.  It  may 
be  necessary  to  seal  this  agent  in  the  cavity  for  twenty-four  hours. 
Cocain  cataphoresis  is,  however,  regarded  as  admissible  in  all  stages  of 
caries. 

The  removal  of  the  softened  dentin  in  these  cases  forms  a  cavity  of 
such  magnitude  that  proximity  to  the  pulp  is  evident.  The  softening 
has  proceeded  for  a  distance  beneath  the  enamel,  so  that  when  all 
softened  dentin  is  cut  away  from  beneath  the  enamel  the  latter  tissue 
overhangs,  unsupported,  the  general  cavity.  These  overhanging  walls 
are  cut  away  until  the  region  of  normal  enamel  is  reached,  and  then  it 
may  be  that  the  walls  still  overhang  the  general  cavity.  It  is  usually  not 
necessary  nor  advisable  to  remove  this  portion  of  enamel.  At  the  com- 
pletion of  excavation,  the  pulp  is  found  to  respond  immediately  to  even 
a  current  of  cool  air,  so  that  protection  of  that  organ  against  thermal 
impulses  is  an  imperative  demand.  It  is  in  this  connection  that  zinc 
phosphate  finds  its  greatest  and  most  useful  field  of  application.  It  is 
used  to  replace  the  greater  bulk  of  the  lost  dentin  after  the  following 
manner  :  the  dentinal  walls  are  sterilized  by  an  application  of  25  per 
cent,  pyrozone  (25  per  cent,  solution  of  hydrogen  dioxid  in  ether),  are 
dried,  and  given  a  coating  of  non-conducting  varnish.  The  varnish 
answers  a  double  purpose  ;  it  lessens  the  moderate  conductivity  of  the 
zinc  phosphate  and  effectually  prevents  the  action  upon  the  dentinal  walls 


318  DENTAL  CARIES. 

of  any  acid  impurities  in  the  cement.  Many  cement-fluids  contain,  as 
impurity,  the  acid  sodium  (dihydrogen  sodium)  phosphate,  NaH2P04. 
This,  when  present  in  a  cement-filling,  causes  the  persistent  acid  reaction 
noted  in  some  cements  ;  this  is  not  only  irritating  to  the  dentinal  fila- 
ments, but  may  cause  superficial  softening.  Zinc  phosphate,  mixed 
stiff,  is  carefully  packed  against  all  of  the  cavity-walls  until  it  is  exactly 
flush  with  the  enamel-margins  and  fills  the  cavity  to  near  the  dentin 
periphery ;  the  cavity  in  the  cement  is  given  a  retentive  form  to  hold 
the  veneer  filling  of  metal  which  is  afterward  to  be  inserted. 

Treatment  of  the  Third  Stage  op  Caries. 

In  the  third  stage  of  caries  complaint  is  made  that  for  some  time  the 
presence  of  cool  or  of  hot  fluids  in  the  mouth  is  productive  of  a  parox- 
ysm of  pain.  After  removing  frail  enamel-walls  and  the  greater  mass 
of  softened  dentin,  including  all  of  that  underlying  enamel,  all  of  the 
decalcified  peripheral  dentin,  it  is  found  that  further  excavation  would 
probably  expose  the  pulp,  which  responds  by  painful  paroxysm  to  even 
gentle  currents  of  cool  air.  As  a  primary  measure,  even  in  the  treat- 
ment of  these  conditions,  irrespective  of  the  filling  operation,  it  is  essen- 
tial that  the  tooth  and  its  neighbors  be  placed  under  a  rubber-dam,  where 
this  device  can  be  applied.  This  applies  with  equal  force  to  operations 
for  more  extensive  disease  ;  the  rubber-dam  is  used  not  only  because  it 
is  impossible  to  effect  perfect  sterilization  without  it ;  but,  in  addition, 
it  is  only  through  the  dryness  and  clear  view  obtained  that  therapeutic 
measures  can  be  applied  with  that  delicacy  and  precision  necessary  to 
their  successful  use. 

The  dentin-covering  of  the  pulp  is  markedly  softened,  and  the  extent 
of  bacterial  invasion  in  the  tubules  is  doubtful.  The  question  arises, 
Shall  excavation  be  made  thorough,  at  the  expense  of  probable  pulp- 
exposure,  or  should  it  cease,  and  the  softened  dentin  be  permitted  to 
remain  ?  General  clinical  experience  speaks  for  the  latter  course.  The 
cavity  in  its  present  condition  is  washed  out  with  a  5  per  cent,  solution 
of  sodium  dioxid,  which  neutralizes  any  acid  present  and  is  antiseptic. 

It  is  evident  that  sterilization  of  the  layer  of  dentin  and  pulp  must 
be  thoroughly  effected  to  assure  a  probable  success,  for  even  under  a 
perfect  filling  anaerobic  organisms  may  make  their  way  to  the  pulp  and 
excite  acute  disease  in  that  organ,  which  is  already  suffering  from  some 
degree  of  debility.  Miller^  demonstrated  that  the  thorough  steriliza- 
tion of  carious  dentin  requires  much  more  time  than  is  usually  given  to 
it.  For  example,  to  effect  the  complete  sterilization  of  a  very  thin 
layer  of  dentin  requires  hours'  immersion  in  strong  carbolic  acid.  Bac- 
teria w^ere  found  in  teeth  which  had  lain  in  concentrated  carbolic  acid 

^Dental  Cosmos,  1891. 


TREATMENT  OF  THE  FOURTH  STAGE  OF  CARIES.  319 

for  nearly  two  hours.  Watery  solutions  of  antiseptics  were  found  to 
penetrate  the  dentin  more  rapidly  than  essential  oils  ;  but  the  agents 
^vhich  eifected  prompt  and  complete  sterilization,  such  as  mercuric 
chlorid  in  1-5  per  cent,  solution,  zinc  chlorid  solutions,  and  others,  are 
of  questionable  utility,  owing  to  their  probable  deleterious  action  upon 
the  pulp.  It  is  preferable,  therefore,  to  permit  a  harmless  antiseptic 
to  act  for  a  longer  period  ;  for  example,  sealing  a  solution  of  thymol  in 
the  cavity  over  night.  The  application  of  a  pledget  of  cotton  moistened 
with  a  25  per  cent,  solution  of  pyrozone  promptly  sterilizes  very  thin 
layers  of  dentin. 

After  sterilization  and  drying,  a  cavity-lining  of  zinc  oxychlorid  is 
indicated.  Clinical  records  show  that  a  layer  of  zinc  oxychlorid  placed 
over  layers  of  decalcified  or  semi-decalcified  dentin  covering  a  pulp,  are 
more  frequently  followed  by  favorable  results  than  ^vith  any  other 
material.  In  the  light  of  present  knowledge  these  benefits  are  attributed 
to  the  antiseptic  property  maintained  by  the  material  for  some  time. 
A  paste  of  the  cement  is  made,  and  a  portion  carried  into  the  cavity, 
^vhere  it  is  immediately  compressed  against  the  cavity-walls  by  means 
of  balls  of  bibulous  paper  which  have  been  prepared  for  this  pur- 
pose. All  of  the  dentinal  walls  are  covered  to  a  depth  of  about  one- 
sixteenth  inch.  As  soon  as  the  material  has  nearly  set,  usually  in  five 
to  ten  minutes,  zinc  phosphate  is  prepared  and  packed  into  the  oxy- 
chlorid matrix,  and  brought  flush  with  the  cavity-margins.  The 
surface-filling  is  then  made  of  metal. 

Treatment  of  the  Fourth  Stage  of  Caries. 

The  fourth  stage  of  caries  is  that  in  which  the  pulp  of  the  tooth  is 
exposed  before  all  of  the  decalcified  dentin  is  removed.  It  is  that 
stage  of  caries  wliich  includes  in  its  treatment  the  operation  of  pulp- 
capping.  A  pulp  which  has  been  uncovered  through  the  loss  of 
overlying  dentin  and  has  been  directly  exposed  to  the  fluids  of  the 
mouth,  is  almost  certainly  infected  with  micro-organisms  ;  but  as  decal- 
cification precedes  bacterial  invasion  in  caries,  it  is  quite  possible  that 
the  dentin  covering  a  pulp  may  be  decalcified  before  direct  invasion  of 
the  pulp  occurs.  The  pathologico-anatomical  condition  of  the  dental 
pulp  is  clinically  judged  by  the  symptomatology  of  the  organ  (see 
Chapter  XVII.),  and  if  the  history  of  the  case  and  the  symptoms 
elicited  at  the  time  of  examination  ffive  no  evidence  of  disease  of  the 
organ,  it  is  adjudged  healthy,  although  the  judgment  formed  may,  in 
many  cases,  be  no  doubt  erroneous.  What  is  usually  taken  as  })re- 
sumptive  evidence  that  a  pulp  has  not  undergone  serious  anatomical 
degeneration,  acute  or  chronic,  is  that  it  has  never  been  the  seat  of 
acute  paroxysmal  pain,  and  that  it  responds  promptly  to  a  current  of 


320  DENTAL  CABIES. 

cold  air.  As  will  be  shown  in  the  chapter  on  Diseases  of  the  Pulp,  if 
paroxysms  of  pain  have  occurred,  and  if  response  to  cool  air  is  delayed^ 
absent,  or  productive  of  prolonged  pain,  it  is  probable  that  serious 
anatomical  degeneration  has  occurred  in  the  pulp. 

The  details  of  cavity-preparation  are  the  same  as  in  the  previous 
case,  except  that  even  the  slightest. pressure  must  be  avoided  in  operat- 
ing close  to  the  pulp.  That  organ  is  very  intolerant  of  even  the  slight- 
est pressure.  The  free  use  of  hydrogen  dioxid  in  solutions  of  neutral 
reaction  should  replace  other  antiseptics.  The  use  of  strong  caustic  or 
coagulating  antiseptics,  even  carbolic  acid,  is  necessarily  productive  of 
injury  to  the  pulp-tissue ;  the  aim  is  to  maintain  the  pulp  in  as  nearly  a^ 
normal  condition  as  possible,  not  to  establish  an  abnormal  one. 

Exposed  Pulp. 

An  exposed  pulp,  even  with  the  probability  that  it  is  non-infected 
and  has  suiFered  no  serious  anatomical  alteration,  is  a  condition  requir- 
ing description  and  treatment  in  itself. 

Diagnosis. — Clinically,  pulp-exposure  is  divided  into,  first,  cases  in 
which  the  carious  process  has  directly  exposed  the  organ  ;  secondly, 
those  in  which  it  is  exposed  through  the  removal  of  softened  dentin 
covering  it ;  thirdly,  those  in  which  it  has  been  exposed  by  carelessness 
or  by  accident  in  excavating. 

If  the  exposure  be  direct,  it  is  detected  visually.  After  isolation  of 
the  tooth,  washing  with  tepid  water,  and  drying,  direct  vision  or  a  re- 
flected image  in  the  mouth-mirror  may  reveal  the  area  of  exposure  as  a 
round  space  occupied  by  a  pinkish-red  body.  If  the  exposure  be  large, 
pulsation  of  the  red  body  may  usually  be  observed.  The  exposure  may 
be  so  slight  that  it  is  invisible,  the  depth  of  the  cavity,  however,  indi- 
cating that  exposure  probably  exists.  Truman  ^  advises  in  these  cases 
that  finely  carded  cotton  be  gently  passed  over  the  cavity-walls,  exposure 
being  detected  by  the  momentary  pain  produced  when  the  fibres  pass 
over  the  area  of  exposure.  A  burnisher  passed  gently  over  the  walls 
of  a  cavity  in  cases  of  suspected  pulp-exposure  will  usually  elicit  a 
quick  start  upon  the  part  of  the  patient  when  the  exposed  spot  is  touched. 
The  previous  existence  or  presence  of  subjective  symptoms,  of  course, 
is  a  diagnostic  sign. 

Prognosis. — Even  presuming  the  absence  of  any  history  of  active 
pulp-disturbance,  the  prognoses  of  the  three  classes  of  cases  differ  ;  prog- 
nosis is  favorable  in  the  reverse  order  of  the  conditions  given.  Again,  the 
prognosis  of  exposed  pulp  is  governed  in  great  measure  by  the  portion  of 
pulp  exposed  ;  if  a  cornu  of  the  organ  be  the  site  of  exposure,  the  prog- 
nosis is  more  favorable  than  if  the  body  of  the  organ  be  exposed.  The 
^  American  System  of  Dentistry,  vol.  i. 


PULP-CAPPING.  321 

most  favorable  prognosis,  all  other  eonditions  being  alike,  would  asso- 
ciate with  accidental  exposure  of  a  cornu  of  a  pulp ;  the  most  unfavor- 
able witli  direct  exposure  by  carious  invasion  of  the  pulp,  at  or  beyond, 
the  neck  of  a  tooth. 

Treatment. — Pulp-capping. — It  is  more  desirable  that  a  pulp- 
capping  should  be  absolutely  neutral,  than  that  it  should  possess  active 
therapeutic  properties.  Theoretically  it  would  be  desirable  to  induce  the 
pulp  to  form  a  plate  of  secondary  dentin  which  should  exactly  repair  the 
area  of  exposure  ;  but  as  there  is  no  means  of  exactly  governing  any 
stimulation  which  may  be  induced,  it  is  preferable  to  use  a  substance 
entirely  neutral  therapeutically.  A  great  number  of  substances  have 
been  recommended  as  pulp-cappers,  but  at  present  only  two  of  them  have 
general  endorsement ;  these  are  a  cement  of  zinc  oxysidfate  and  a  paste 
of  one  of  the  essential  oils  with  zinc  oxid.  Solutions  of  gutta-percha  in 
chloroform,  disks  of  softened  gutta-percha,  and  zinc-oxychlorid  cement 
are  also  used,  but  not  to  the  extent  that  the  first  mentioned  are.  Zinc  oxy- 
chlorid,  even  when  the  fluid  is  dilute,  may  induce  irritation,  but  in  some 
cases  it  has  proved  an  admirable  material.  Gutta-percha  preparations, 
bland  as  they  are,  do  not  appear  to  serve  so  well  as  the  cement  of  zinc 
oxysulfate  or  the  zinc  oxid  and  oil  paste. 

Whatever  material  be  used,  it  is  essential  that  not  the  slightest  press- 
ure be  exercised  in  its  application.  The  capping-paste  is  best  and  most 
accurately  carried  into  place  through  the  medium  of  a  concave  metal 
disk. 

The  oil  and  oxid  paste  is  made  by  adding  zinc  oxid  (cement  powder) 
to  a  drop  of  oil  of  cloves  until  a  moderately  thick  paste  is  made.  The 
fluid  of  the  oxysulfate  cement  is  a  saturated  solution  of  zinc  sulfate  in 
water ;  the  powder  is  chemically  pure,  zinc  oxid,  uncalcined.  If  the 
powder  contain  traces  of  arsenic,  pulp-devitalization  may  ensue.  Fluid 
and  powder  are  made  into  a  thin  paste.  The  cement  hardens  very 
quickly  into  a  white  porous  body  of  about  the  hardness  of  plaster  of 
Paris.  Whichever  paste  is  used,  the  concave  disk  is  filled  with  it,  the 
disk  being  of  a  size  to  set  firmly  on  the  dentin  all  around  the  exposure. 
It  is  caught  upon  one  side  in  the  jaws  of  a  delicate  pair  of  pliers  and 
carried  quickly  to  the  cavity  ;  it  is  not  set  squarely  over  the  exposure, 
but  one  edge  is  laid  down  first,  and  the  disk  delicately  lowered  until  it 
rests  upon  the  dentin  and  covers  the  exposure ;  the  excess  of  cement 
oozes  from  the  side  of  the  disk  last  .to  touch  the  dentin.  No  sensation 
should  be  caused  by  the  operation.  If  zinc  oxysulfate  has  been  used, 
the  surplus  paste  is  to  remain  ;  if  the  oil  of  cloves,  the  surplus  is  wiped 
away.  The  cap  is  retained  in  place  and  non-conductivity  assured 
by  lining  the  cavity  with  a  layer  of  zinc  phosphate,  so  thin  that  it  will 
flow.     It  is  the  usual  practice  to  complete  the  filling  with  zinc  phos- 

21 


322  DENTAL  CARIES. 

phate  or  gutta-percha,  and  if,  at  the  end  of  six  months,  no  evidences 
of  disturbance  have  occurred  and  the  pulp  respond  normally  to  applica- 
tions of  cold,  a  permanent  filling  is  inserted. 

Statistics  regarding  the  success  or  failure  of  efforts  at  the  conserva- 
tion of  the  dental  pulp  have  been  presented  in  such  manner  as  to  make 
their  value  extremely  doubtful.  One  reports  the  capping  of  all  cases 
of  exposure  and  gives  the  percentage  of  success.  Another  condemns 
the  operation  in  toto,  and  states  that  exposure  always  indicates  imme- 
diate devitalization  of  the  pulp,  and  yet  in  both  cases  the  probable 
morbid  anatomical  conditions  which  are  deemed  to  warrant  either  course 
are  not  set  forth.  The  clinical  records  of  those  who  practise  the  ope- 
ration after  the  method  and  under  the  conditions  here  set  forth 
warrant  the  judicious  practice  of  pulp-capping.  No  modern  path- 
ologist or  well-informed  practitioner  ever  questions  the  great  advantage 
of  having  vital  and  normal  pulps  in  teeth  ;  pulpless  teeth  are  less  strong  ; 
they  are  liable  to  discolorations,  and  prone  to  pericementitis,  even  when 
skilfully  treated. 

Capped  pulps  may  give  almost  immediate  evidences  of  subjective 
disturbances,  or  the  latter  may  not  appear  for  years ;  but  if  the  pulp 
remain  quiescent  for  a  year,  a  successful  issue  is  accepted.  Exaggera- 
tions or  alterations  in  the  mode  of  reaction  to  thermal  impulses  indicate 
an  unfavorable  issue,  as  do  also  pains  referred  to  the  region  of  the 
treated  tooth. 

Prophylaxis  op  Caries. 

The  prophylaxis  or  prevention  of  dental  caries  implies  the  removal 
of  its  exciting  and,  as  far  as  possible,  its  predisposing  causes.  The 
removal  of  the  exciting  causes  implies  the  destruction  of  ferments  and 
the  removal  of  fermentable  material. 

For  the  growth  of  the  active  causes  of  caries  two  conditions  appear 
to  be  essential — that  necessary  for  the  life  of  all  organisms,  a  food- 
supply,  fermentable  material ;  and,  secondly,  some  undetermined  bodily 
conditions  which  favor  or  deter  their  growth.  The  manner  in  which 
the  constitutional  condition  reacts  upon  the  secretions  and  tissues  of  the 
mouth,  so  that  favorable  or  unfavorable  conditions  exist  for  the  growth 
of  lactic  ferments,  is  purely  conjectural ;  but  it  may  be  assumed  that 
in  a  perfectly  healthy  individual,  one  having  entirely  normal  oral  con- 
ditions, the  soil  for  the  growth  of  organisms  is  most  unsuitable. 

It  is  freely  conceded  that  bodily  states  react  upon  the  oral  tissues  and 
alter  their  physiological  relation,  but  the  chief  oral  disturbances  are,  no 
doubt,  of  purely  local  origin.  While  it  is  unquestionably  true  that  the 
correction  of  morbid  conditions  in  other  parts  of  the  body  may  be  fol- 
lowed by  a  cessation  of  oral  disturbances,  the  extent  of  the  changes  thus 


PROPHYLAXIS  OF  CARIES.  323 

brought  about  are  not  comparable,  in  point  of  extent,  with  the  changes 
induced  by  rational  local  therapeusis. 

In  general  terms  the  prevention  of  dental  caries  begins  with 
the  correction  of  morbid  physiology  in  all  parts  of  the  body.  If 
general  disease-causes — disorders  of  food-metabolism,  of  the  blood- 
making  organs,  the  blood-distributing  apparatus,  and  the  excretory 
organs — be  in  operation,  a  lowered  vitality  is  present  everywhere, 
including  the  mouth,  and,  no  doubt,  in  the  vital  tissues  of  the  teeth; 
Assumiuff  that  such  causes  and  morbid  conditions  have  been  remedied, 
are  irremediable,  or  not  treated,  the  local  measures  are  all-important. 
These  are  physiological,  mechanical,  and  medicinal.  The  physiological 
and  mechanical  features  both  have  to  do  with  the  removal  of  ferment- 
able material.  Normally  the  movements  of  mastication  subject  the 
teeth  to  friction,  through  the  medium  of  food-stuffs  ;  they  cause  an 
increased  flow  of  saliva,  which  is  pumped  between  the  teeth  and  carried 
around  and  over  them  in  currents.  If  the  movements  of  mastication 
are  lessened,  not  only  is  the  extent  of  mechanical  rubbing  lessened,  but 
the  excretion  of  saliva  is  diminished,  and  after  a  time  becomes  altered 
in  character.  The  coarser  fibrous  foods  require  more  mastication  and 
leave  less  debris  than  the  soft,  pulpy  foods.  Normal  physiological  use 
is,  then,  an  important  feature  in  the  prevention  of  caries.  If  the  indi- 
vidual can  be  persuaded  to  lessen  the  amount  of  cooked  starches,  pastry, 
etc.,  in  the  dietary,  and  substitute  food  requiring  more  mastication,  the 
amount  of  fermentable  debris  is  correspondingly  reduced. 

The  presence  of  debris  between  the  teeth  and  about  their  necks 
affords  not  only  in  itself  the  material  for  the  generation  of  lactic  acid, 
but  furnishes  a  medium  in  which  soluble  sugars  may  be  retained,  which 
undergo  transformation  into  lactic  acid.  The  importance  of  freeing  the 
teeth  from  food-deposits,  inspissated  mucus,  calculi,  etc.,  is  generally 
recognized,  it  having  been  noted  that  caries  is  markedly  lessened  in 
well-kept  dentures.  The  means  of  accomplishing  this  cleansing  are 
largely  mechanical — by  the  use  of  tooth-picks,  brushes,  and  floss-silk. 
The  tooth-pick  and  floss-silk  are  used  to  partially  (they  cannot  com- 
pletely) remove  debris  from  the  approximal  surfaces  of  the  teeth  ;  the 
tooth-brush  removes  those  from  the  occlusal,  buccal,  labial,  and  lingual 
surfaces.  Were  it  possible  through  such  means  to  thoroughly  remove 
all  debris,  caries  might  be  reduced  to  the  position  of  an  unusual  disease  ; 
but  it  is  because  of  their  comparative  inefficiency  that  painstaking  cleans- 
ing, while  lessening,  does  not  prevent  caries. 

DENTIFRICES. 

To  aid  the  mechanical  action  of  the  tooth-brush  it  is  usual  to  charge 
the  brush  with  cleansing  agents — dentifrices  ;  these  are  in  the  form  of 


324  DENTAL  CARIES. 

powders,  pastes,  and  soaps.  The  powder  should  not  be  gritty  ;  if  it 
contain  sharp  particles,  as  charcoal,  pumice,  etc.,  the  powder  remains  in 
the  small  spaces  between  the  gums  and  teeth  and  acts  as  an  irritant. 
The  usual  basis  of  all  powders  is  calcium  carbonate,  in  the  form  of  pre- 
cipitated chalk  ;  this  serves  as  a  mild  abrasive  and  neutralizes  any  free 
acids  with  which  it  is  brought  in  contact.  Magnesium  carbonate  or 
hydrate  is  to  be  preferred,  as  its  particles  are  smoother  and  have  less 
tendency  to  collect  between  the  teeth.  It  is  customary  to  combine  with 
the  chalk  or  magnesium  from  one-third  to  one-half  its  bulk  of  orris- 
powder  for  the  supposed  tonic  influence  of  the  latter  upon  the  soft  tissues. 
To  this  basal  powder  are  added  flavoring-substances  and  sugar,  to  render 
the  dentifrice  more  agreeable.  Oils  of  lemon,  gaultheria,  rose,  etc.,  are 
used  for  flavoring,  and  .sugar  to  sweeten  the  powder.  Sugar,  however, 
should  be  always  omitted  from  dentifrices  ;  it  but  adds  to  the  ferment- 
able material  present  in  the  mouth.  To  sweeten  dentifrices  saccharin 
should  be  used,  of  which  but  a  minute  portion  is  required ;  it  is  also  an 
antiseptic. 

Tooth-pastes  contain  about  the  same  ingredients  as  an  ordinary 
tooth-powder,  made  into  a  paste  with  honey  and  glycerin ;  their  use  is 
deprecated  for  this  reason. 

Tooth-soaps  have  the  great  advantage  of  saponifying  and  removing 
the  fatty  deposits  from  the  surfaces  of  the  teeth,  large  areas  of  retention 
which  are  but  partially  cleansed  by  powders.  They  are  made  by  adding 
about  one-third  by  volume  of  powdered  castile  soap  to  ordinary  tooth- 
powder.  Antiseptics  may  be  combined  with  tooth-soap  with  marked 
advantage. 

The  last  and  a  highly  important  consideration  in  the  matter  of  pro- 
phylaxis is  the  destruction  of  the  active  organisms.  The  routine  of 
tooth-cleansing  includes  the  use  of  the  tooth-pick,  floss-silk,  brush, 
and  dentifrice,  before  the  germicides  proper  are  used.  Unless  the  foreign 
deposits  be  first  removed,  the  action  of  germicides  is  mechanically 
interfered  with  where  they  are  most  needed.  It  is  essential  that  the 
antiseptic  should  be  held  in  contact  with  the  teeth  for  a  long  enough 
period  to  act  as  a  germicide  ;  to  merely  take  it  into  the  mouth  and  eject 
it  in  a  few  seconds  accomplishes  but  little  good.  The  most  effective 
method  of  using  oral  germicides  is  that  suggested  by  Ottolengui,  to 
spray  by  means  of  an  atomizer  a  solution  of  the  germicide  between  all 
of  the  teeth  and  over  all  of  their  surfaces. 

Miller  ^  has  tested  the  strength  of  solution  of  antiseptics  admissible 
for  this  purpose,  to  determine  which  act  most  promptly  and  within  the 
necessary  time — about  one  minute  : 

^  Micro-organisms  of  the  Human  Mouth. 


PROPHYLAXIS  OF  CARIES. 


325 


Antiseptic. 


Salicylic  acid 

Benzoic  acid 

Listerine 

Salicylic  acid 

Bichlorid  of  niCM-cury 

Benzoic  acid 

Borobenzoic  acid      

Thymol 

Bichlorid  of  niercary 

Peroxid  of  liydrogen 

Carbolic  acid 

Oil  of  peppermint  in  agreeable  strength 

Permanganate  of  potassium 

Boric  acid  .    .  

Oil  of  wintergreen 

Tincture  of  cinchona 

Lime-water 


Concentration. 

1  :  100 
1:100 


1  :  200 
1  :  2500 
1  :  200 
1  :  175 
I  : 1500 
1  : 5000 
10  per  cent. 
1:100 


1 :  4000 
1:50 


1:18 


Time  necessary  for  devi- 
talization. 


^  minute. 
i—h  minute. 


1-2  minutes. 

1-2 

2-4 

2-5  " 
10-15  " 
10-15      " 

5-10      " 
More  than  15  minutes. 
"        "      15       " 
«        "      15       " 
"        "      15       " 
No  action. 


Combinations  of  antiseptics  are  desirable  to  act  as  stimulants  and,  at 
times,  astringents  to  the  soft  tissues.  Such  prescriptions  as  listerine, 
thymozone,  borolyptol,  etc.  (combinations  of  benzoic  acid,  thymol,  for- 
malin), and  others,  with  such  agents  as  eucalyptus,  which  exercise  a 
favorable  influence  upon  the  vitality  of  the  soft  tissues,  are  used  with 
much  advantage.  None  but  favorable  results  are  noted  after  their  long- 
continued  use.     It  is  customary  to  dilute  them  before  using. 

The  times  for  the  thorough  cleansing  of  the  teeth  should  be  before 
retiring  and  after  rising,  particularly  the  latter.  The  periodical  cleans- 
ing of  the  teeth  by  the  dental  operator  is  an  important  feature  in  caries 
prophylaxis. 


SECTION  IV. 

DISEASES  OF  THE  DENTAL   PULP. 


CHAPTER  XVII. 
COXSTRUCTIVE  DISEASES. 

Diseases  of  the  dental  pulp  are  both  acute  and  chronic.  Ac- 
cording to  the  anatomical  features,  they  may  also  be  divided  into 
constructive  and  destructive ;  and  as  to  their  character  into  functional 
and  structural.  The  acute  diseases  are  usually  functional  and  destruc- 
tive ;  in  the  chronic,  structural  and  constructive  changes  are  commonly 
noted.  Constructive  diseases  of  the  dental  pulp  are  those  attended  by 
the  formation  of  deposits  of  new  masses  of  dentinal  substance.  Destruc- 
tive diseases  are  those  which  cause  retrogressive  and  necrotic  changes  in 
the  tissues  of  the  pulp.  The  essential  difference  between  the  two  classes 
of  diseases  is  in  the  mode  and  character  of  the  degeneration — the  one  is 
acute,  the  other  chronic. 

Pathologically  there  is  no  abrupt  line  of  separation  between  those 
disorders  usually  termed  diseases  of  the  dental  pulp  and  those  which 
are  described  under  the  head  of  diseases  of  the  live  dentin.  As  soon  as 
the  dentin  of  the  crown  of  a  tooth  is  deprived  of  a  portion  of  its  normal 
protective  covering,  the  enamel,  either  through  chemical  solution  inci- 
dent to  the  first  phase  of  dental  caries,  or  from  mechanical  abrasion,  the 
vital  portions  of  the  dentin  are  subjected  to  new  and  abnormal  con- 
ditions. These  vital  portions  being  in  reality  prolongations  of  the 
peripheral  cells  of  the  pulp,  it  is  evident  that  the  morbid  conditions  en- 
gendered by  their  exposure  are  expressions  of  pulp-disturbance,  and  we 
should  expect  to  find  reactionary  effects  upon  the  part  of  the  pulp. 
Depending  upon  the  severity  of  the  irritation  and  the  length  or  number 
of  times  sources  of  irritation  have  been  in  operation,  evidences  of  func- 
tional and  structural  disorders  in  the  body  of  the  dental  pulp  are 
observed. 

Post-mortem  knowledge  of  structural  diseases  of  the  dental  pulp  is 
comparatively  complete,  but  a  parallel  knowledge  of  the  exact  nature 
of  the  causes  producing  definite  and  recognizable  conditions,  together 
with  the  symptoms  which  precede  and  accompany  the  several  morbid 

327 


328  CONSTRUCTIVE  DISEASES. 

states,  is  incomplete.  In  the  absence  of  precise  information  as  to  the 
association  between  disease-causes,  their  symptoms  and  effects,  physio- 
logical and  pathological,  the  practitioner  bases  his  diagnosis  of  the  ana- 
tomical condition  of  the  pulp  on  symptoms  which  he  is  enabled  to  elicit 
by  certain  tests,  and  by  the  history  furnished  by  the  patient.  The  tests 
applied  and  histories  obtained,  direct  attention  to  the  vascular  system  of 
the  pulj)  as  the  primary  cause  of  many,  or  most,  of  the  conditions  of  the 
organ  which  are  attended  by  paroxysmal  and  reflex  pains.  The  reac- 
tions to  tests  occur  both  with  and  without  exposure  of  the  pulp  to  exter- 
nal sources  of  bacterial  infection,  although  they  are  found  in  the  vast 
majority  of  cases  where  bacterial  invasion  is  a  probability. 

Symptomatology  of  the  Pulp. 

Writers  upon  dental  pathology,  during  at  least  the  past  twenty-five 
years,  have  called  attention  to  the  fact  that  pain  produced  through 
the  irritation  of  the  dental  pulp  is  rarely  referred  to  its  point  of 
origin  ;  that  is,  diseases  of  the  pulp  are,  as  a  rule,  characterized  by 
reflected  pains.  G.  V.  Black  ^  has  clearly  set  forth  the  causes  and 
reason  of  this  phenomenon.  "  The  pulp  of  a  tooth  is  not  its  tactile 
organ ;  that  is,  it  does  not  possess  the  sense  of  location.  The  only 
stimulus  to  which  it  responds  in  its  normal  state,  when  encased  in  an 
unbroken  chamber  of  dentin,  which  is  perfectly  sheathed  with  enamel,  is 
applications  of  heat  or  cold.  Far  removed  in  its  normal  state  from 
situations  in  which  a  tactile  sense  could  perform  any  physiological 
function,  such  a  sense  would  be  useless.  Organs  in  which  the  tactile 
sense  is  absent  and  in  which  it  would  be  perhaps  superfluous,  when  the 
seat  of  disease  have  the  pain  incidental  to  the  disease  reflected  to  other 
parts ;  for  example,  in  hip-joint  disease,  pain  at  the  inner  side  of  the 
knee  is  a  diagnostic  sign  ;  in  inflammations  of  the  iris  the  pain  is  referred 
to  the  brow ;  pain  at  the  orifice  of  the  urethra  is  indicative  of  disease  of 
the  bladder,  and  so  on.  So  with  irritation  of  the  dental  pulp,  the  pain 
is  indefinitely  or  vaguely  located.  In  those  cases  where  pain  is  referred 
to  the  tooth  irritated,  there  are  associated  conditions  which  produce  a 
response  of  the  true  tactile  organ  of  the  tooth,  the  pericementum." 

The  test  by  which  the  anatomical  and  physiological  conditions  of 
the  pulp  are  judged  is  the  specific  stimulus  to  which  the  pulp  is  re- 
sponsive— changes  of  thermal  impulse.  The  phenomena  induced  by 
applications  of  water  whose  temperature  is  above  or. below  that  of 
the  body,  the  extent  and  promptitude  of  the  response,  and  the  tem- 
peratures inducing  it,  are  the  only  clinical  means  available  for  deter- 
mining the  condition  of  the  pulp,  the  prognosis  of  its  diseases,  and 
directing  the  mode  of  their  treatment. 

^  American  System  of  Dentistry,  vol.  i. 


SYMPTOMATOLOGY  OF  THE  PULP.  329 

It  was  pointed  out  by  Black  ^  that  if  a  healthy  tooth  be  isolated  by 
a  double  layer  of  rubber-dam,  and  a  jet  of  water  at  a  temperature  of 
40"^  F.  be  directed  against  the  tooth,  a  paroxysm  of  pain  is  produced.  A 
jet  of  hot  water  will  also  induce  a  similar  pain,  and  if  the  patient's  eyes 
be  shielded  no  difference  in  the  sensations  is  noted.  That  is,  the  pulp 
responds  to  thermal  stimuli,  hot  or  cold  indifferently.  The  organ  is 
accustomed  to  variations  of  temperature  between  60°  and  105°-110°  F., 
and  within  this  range,  in  a  condition  of  health,  takes  no  apparent  cog- 
nizance of  this  degree  of  change. 

With  a  decrease  in  the  amount  of  dentin  covering  the  pulp — i.  e., 
with  the  advance  of  caries — the  reaction  to  thermal  stimuli  increases  in 
promptness,  until,  when  the  pulp  is  nearly  exposed,  the  response  is 
immediate.  Succeeding  this,  is  noted  prompt  response  to  lesser  degrees 
of  temperature-change,  until  the  pulp  comes  to  respond  immediately  to 
water  at  a  temperature  of  70°  F.,  or  thereabout,  and  slightly  over  the 
bodily  temperature,  102°  F.  Later,  another  feature  makes  its  appear- 
ance ;  instead  of  a  sharp  contraction-pain,  applications  of  moderate 
thermal  stimuli  are  followed  l)y  a  heavy,  throbbing  pain.  Later,  similar 
pains  occur  in  the  absence  of  tangible  external  sources  of  irritation.  In 
the  ordinary  sequence  of  events  intense  pain  is  later  caused  by  hot 
applications,  and  cold  applications  afford  relief. 

The  response  to  thermal  stimuli  may  pursue  the  opposite  course. 
The  normally  prompt  response  is  followed  by  delays  in  reaction,  until 
it  is  onlv  after  the  continued  application  of  cold  to  the  exterior  of  a 
tooth  that  a  paroxysm  of  pain  is  induced.  In  these  cases  there  follows 
after  a  long  time  an  increasing  response  to  heat,  as  in  the  former 
instance,  the  reaction  occurring  only  upon  decided  or  prolonged  heat- 
stimuli.  Following  upon  the  period  of  increased  response  to  heat,  in 
both  cases  there  comes  a  period  of  quiescence,  in  which  there  is  no  re- 
sponse whatever  to  applications  of  intense  cold,  even  that  produced  by 
the  evaporation  of  a  spray  of  ethyl  or  methyl  chlorid — i.  e.,  the  sensory 
function  of  the  pulp  is  paralyzed. 

These  are  the  available  subjective  evidences  of  the  anatomical  con- 
dition of  the  pulp  ;  Avhile  they  indicate  with  a  degree  of  accuracy,  use- 
ful in  clinical  work,  the  alterations  in  the  pulp,  the  exact  relations 
between  the  reactions  and  the  morbid  anatomy  of  the  organ  are  not 
entirely  clear.  In  the  light  of  present  knowledge  it  is  assumed  that, 
in  consequence  of  loss  of  the  normal  protective  covering  of  the  pulp,  its 
sensory  and  perhaps  vasomotor  nerve-fibres  become  stimulated,  over- 
stimulated,  irritated,  then  paralyzed  by  thermal  stimuli  in  the  progress 
of  caries.  The  bloodvessels,  which  retained  their  tonus  up  to  a  certain 
point,  suffer  vasomotor  irritation  ;  next,  paralysis  leading  to  their  dila- 
^  American  Systevi  of  Dentistry,  vol.  i. 


330  CONSTRUCTIVE  DISEASES. 

tation  and  to  the  throbbing  pain.  Later,  even  change  of  posture  is 
sufficient  to  cause  distention  of  the  paralyzed  vessels,  hence  pain  in 
resuming  the  reclining  position.  Stimulation  by  cold,  until  the  later 
stages,  causes  a  sharp  continuous  pain,  ascribed  to  the  paroxysmal  con- 
traction of  the  vessels ;  although  unquestionably  specific,  sensory  nerve 
reaction  is  involved.  In  the  stages  of  paralysis,  heat  causes  further  dis- 
tention of  the  vessels,  and,  if  adventitious  gases  be  present,  causes  their 
expansion  with  pressure  upon  nerve-filaments. 

The  decreasing  and  delayed  response  to  thermal  stimuli  must  be 
referred  to  two  sources  :  first,  an  increase  in  the  non-conducting  cover- 
ing of  the  pulp — /.  e.,  a  lessening  of  the  amount  of  the  fluid  contents 
of  the  dentinal  tubuli  and  a  thickening  of  the  dentinal  walls,  which 
necessarily  implies  a  recession  of  the  pulp  from  its  normal  position  ; 
secondly,  to  degeneration  of  the  sensory  nerve-fibres  themselves ;  and, 
thirdly,  changes  in  the  walls  of  or  about  the  bloodvessels,  which  check 
vasomotor  response  and  changes  in  the  calibre  of  the  vessels.  These 
two  classes  of  reactions  still  further  emphasize  the  division  of  pulp- 
diseases  into  two  types,  the  acute  and  chronic ;  the  first  class  of  reac- 
tion is  associated  Avith  the  acute  destructive  diseases,  the  second  with 
the  chronic  constructive  but  degenerative  conditions. 

Constructive  Diseases  op  the  Dental  Pulp. 

The  constructive  diseases  of  the  dental  pulp  include  all  the  secondary 
dentin  formations,  tubular  calcification,  the  formation  of  pulp-nodules, 
and  calcareous  degeneration  of  the  pulp. 

TUBULAR   CALCIFICATION. 

Definition. — By  tubular  calcification,  or,  to  express  the  condition 
more  accurately,  tubular  dentinification,  are  meant  those  changes  that 
occur  in  the  dentin  which  lead  to  an  obliteration  of  the  dentinal  tubuli 
by  constructive  changes  in  the  walls  of  the  tubules. 

Causes  and  Occurrence. — A  mild  degree  of  irritation,  not  passing 
the  stage  inducing  constructive  metamorphosis,  and  apparently  caused 
by  heightened  thermal  sensitivity.  It  occurs  in  the  course  of  mechanical 
abrasion  and  erosion  of  the  teeth,  under  metallic  fillings  ;  and  probably 
a  modification  of  the  process  precedes  the  slow  invasion  of  dental  caries. 
It  occurs  in  some  degree  as  a  normal  vital  change  due  to  age,  and  is 
common  in  persons  who  are  victims' of  the  gouty  or  rheumatic  diathesis. 

Effects. — The  altered  dentin  becomes  translucent,  acquiring  a  horn- 
like appearance.  While  there  is  no  doubt  that  the  existence  of  this 
condition  of  the  dentin  delays  the  disintegration  of  the  tissue,  it  does 
not  prevent  it. 


CONSTRUCTIVE  DISEASES  OF  THE  DENTAL  PULP. 


331 


SECONDARY    DENTIN. 

Formations  of  dentinal  tissue  in  the  pulp-chamber  are  of  several 
varieties ;  the  one  under  immediate  discussion  is  that  deposited  upon 
and  forming  part  of  the  pulp-chamber  wall,  lessening  the  volume  of 
the  cavity  and  of  the  dental  pulp. 

Causes. — A  lessening  of  the  volume  of  the  pulp-chamber — i.  e., 
thickening  of  the  dentinal  walls — is  a  normal  change  of  the  teeth  occur- 
ring with  age.  The  change  of  senility  is  caused  by  a  deposition  of  nor- 
mal dentin  ;  the  lumen  of  the  tubule  lessens  ;  the  odontoblasts  recede, 
and  grow  smaller  and  less  in  number.  This  change  is  accompanied  by 
increase  in  the  fibrous  elements  of  the  pulp ;  in  other  words,  sclerotic 
chantres  occur  Avith  ag-e. 

It  is  to  be  remembered  that  the  formative  activity  of  the  pulp  is  not 
exhausted  until  the  pulp  is  almost  obliterated,  and  when  this  occurs  the 
organ  has  completed  its  physiological  office  and  undergoes  degeneration. 


Fig.  262. 


Fig.  263. 


Fig.  262.— Secondary  dentin,  flllingthepulp-chamberincaseof  abrasion  of  a  cuspid  tooth:  a,  portion 
lost  by  abrasion  ;  c,  abraded  surface ;  rf,  secondary  dentin,  filling  a  portion  of  the  pulp-chamber, 
and  acting  as  a  protection  to  the  pulp ;  e,  slender  point  of  the  pulp ;  irregular  deposits  are  seen 
on  the  walls  of  the  pulp-chamber,  as  at/;  g,  cylindrical  calcifications  in  the  root-portion  of  the 
pulp-chamber. 

Fig.  263.— Calcification,  or  deposit  of  secondary  dentin,  resulting  from  caries  of  an  incisor:  A,  dia- 
gram of  section  of  incisor,  shovving  caries  at  a,  and  secondary  dentin  at  6.  B,  illustration 
magnified  200  diameters,  to  show  the  tissue  of  the  secondary  dentin  :  a,  pulp-chamber  ;  6, 6,  sec- 
ondary dentin  ;  c,  primary  dentin.  It  will  be  noticed  that  the  dentinal  tubes  in  the  secondary 
dentin  gradually  disappear,  giving  place  to  a  clear  calcification.    (Black.) 

As  will  be  seen  in  the  discussion  of  the  several  constructive  changes, 
variations  in  the  conditions  of  the  teeth  may  bring  about  the  premature 


332 


CONSTRUCTIVE  DISEASES. 


exhaustion  of  the  formative  activity,  with  its  consequence,  atrophy  of 
the  pulp. 

The  formation  of  secondary  dentin  implies  the  action  of  a  localized 
stimulation  of  formative  activity  of  the  odontoblasts.  It  is  probable 
that  all  of  the  cases  of  localized  irritation  may  by  careful  investigation 
be  resolved  into  an  increased  conductivity  ;  that  is,  a  lessened  non- 
conductivity  through  a  defined  path. 

Secondary  deposits  are  commonly  found  associated  with  abrasion, 
erosion,  the  slow  advance  of  dental  caries,  and  with  metallic  fillings  in 
proximity  with  the  pul])! 

Patholog-y  and  Morbid  Anatomy. — The  formation  is  noted  oppo- 
site some  area  of  injury  (Figs.  262,  263),  and  may  be  easily  distin- 
guished from  the  normal  dentin.  Viewed  macroscopically  it  is  usually 
seen  to  differ  from  normal  dentin  in  its  degree  of  translucency  (Fig. 
264),  and  viewed  microscopically  there  is  a  sharp  change  of  direction 

Fig.  264. 


Secondary  dentin,  from  the  same  specimen  as  Fig.  262,  magnified  sufficiently  to  show  the  difference 
in  primary  and  secondary  tissue  :  a,  abraded  surface  of  crown :  b,  secondary  dentin  ;  c,  primary 
dentin ;  d,  junction  of  primary  with  secondary  dentin ;  e,  remains  of  pulp-tissue  ;  /,  small  oval 
masses  of  calcific  material.    (Black.) 


of  the  tubules  which  abru])tly  marks  oflP  the  secondary  from  the  normal 
dentin.  So  long  as  the  stimulation  is  uniform  and  localized,  the  new 
formation  appears  to  be  limited  to  an  amount  which  will  equalize  the 
rate  of  condnctivitv  in  the  dentin. 


CONSTRUCTIVE  DISEASES  OF  THE  DESTAL  PULP. 


333 


The  growth  excited  by  caries  presents  some  features  differing  markedly 
from  those  excited  by  abrasion/ 

Growths  in  Abrasion. — The  growths  excited  by  abrasion  have 
more  regularity  of  structure,  and  the  gradual  obliteration  of  the  pulp- 
chamber  occurs  in  more  regular  lines  (Fig.   265).     In  cases  affectine: 

double  or  triple  rooted  teeth  Black  found 
the  deposits  limited  to  the  pulp-chamber 
and  to  the  bulbous  portions  of  the  pulp, 
the  diameter  of  the  root-canal  being 
diminished  only  at  its  entrance  ;  the 
deposits  may  extend  for  some  distance 
up  the  canals,  but  never  far,  a  condition 
different  from  that  noted  in  dej)Osits  ex- 
cited by  other  causes. 

"  Secondary  growths  in  cases  of  abra- 

Illustration  of  the  narrowing  of  the  FiG.   266. 

pulp-chamber  in  a  molar  (superior) 
by  the  deposit  of  secondary  den- 
tin resulting  from  abrasion,  showing 
the  portions  of  the  chamber  in  which 
the  deposit  usually  occurs.  The  light- 
shaded  portion  (6)  shows  the  original 
dimensions  of  the  chamber,  which  in 
.  this  instance  seem  to  have  been  pret- 
ty large  ;  a,  a  point  of  deep  abrasion  ; 

c,  c,  remaining  pulp-chamber,  which 
is  mostly  filled  with  irregular  masses  : 

d,  one  of  the  root-canals.  It  will  be 
observed  that  the  narrowing  of  the 
root-canal  is  within  the  original  pulp- 
chamber.    (Black.) 


P.D.,  primary  dentin;  S.D.,  secondary  dentin, 
P,  pulp-chamber ;  D,  nodules. 


sion  are  not  confined  alone  to  the  abraded  teeth,  but  other  teeth  which 
have  escaped  wear  may  be  affected  in  equal  degree.  In  all  of  these 
cases  there  is  direct  evidence  that  the  odontoblastic  layer  has  been  stimu- 
lated to  increased  activity  and  produced  the  regular  secondary  deposi- 
tion." 

Growths  excited  by  caries  usually  lack  the  regularity  observed 
in  the  former  cases,  the  difference  being,  no  douljt,  attributable  to  the 
nature  and  intensity  of  the  irritation  produced.  While,  as  shown, 
stimulation  of  the  dental  pulp  results  in  a  somewhat  regular  and  out- 
lined functional  activity,  other  grades  of  pulp-disturbance  lack  this 
continuous  degree  of  respon.se,  and  formations  are  irregular  ;  and  by  the 
same  rule  the  existence  of  irregular  deposits  is  an  indication  of  grades 
and  varieties  of  pulp-disturbances  in  excess  of  the  stimulation  ;  they 
indicate  irritations  and  hyperaemias.  This  is  Avell  illustrated  in  the  case 
from  which  the  appended  figure  (Fig.  266)  was  taken.  The  carious 
^  Black,  American  System  of  Dentistri/,  vol.  i. 


334  CONSTRUCTIVE  DISEASES. 

process  was  progressing  slowly  in  the  anterior  segment  of  an  upper 
first  molar,  the  second  bicuspid  being  absent.  When  the  cavity  had 
reached  the  second  stage  of  invasion,  it  was  filled  with  zinc  phosjDhate. 
At  this  time  it  responded  normally  to  the  thermal  test.  After  four  years, 
vague  discomfort  was  felt  in  the  region,  and  in  another  year  was  referred 
to  the  filled  tooth,  which  responded  faintly  to  hot  applications  and  not  at 
all  to  cold.  Diagnosis  :  pulp  in  last  stages  of  degeneration.  Upon  open- 
ing the  tooth  the  jDortion  of  the  chamber  opposite  the  original  caries,  and 
beyond,  was  found  much  contracted  by  a  deposit  of  secondary  dentin; 
the  bulbous  portion  of  the  chamber  and  canals  contained  large  loose 
dentinal  tumors,  that  in  the  palatal  root  almost  filling  the  canal.  These 
deposits  were  of  conglomerate  nature,  the  elements  of  pulp-tissue  being 
caught  in  their  substance. 

The  formation  of  regular  deposits  of  secondary  dentin,  causing 
uniform  or  nearly  uniform  contraction  of  the  pulp-chamber,  has  no 
clinical  significance  in  point  of  therapeutical  indications.  The  process 
must  be  regarded  as  conservative  in  character,  although  unquestionably 
the  formation  of  secondary  dentin  hastens  the  physiological  exhaustion 
of  the  pulp-tissue.  Black  ^  calls  specific  attention  to  the  changes  in  the 
character  of  extensive  secondary  deposits,  that  at  first  the  new  structure 
contains  nearly  the  normal  number  of  tubules,  which  later  become  fewer 
— i.  €.,  the  odontoblasts  have  lessened  in  number  and  later  structureless 
granular  dentinal  matter  is  found. 

Other  forms  of  calcic  deposits  are  found  in  the  pulp-chamber, 
mechanically  displacing  portions  of  the  pulp-substance,  occupying  the 
interstices,  enveloping  the  pulp-elements  ;  and  again  the  tissue-elements 
themselves  appear  to  undergo  calcareous  degeneration.  These  all 
appear  to  be  due  to  the  occurrence  of  higher  grades  of  pulp-disturb- 
ance and  vascular  reaction  than  represented  in  the  case  of  orderly 
deposits  of  true  dentinal  substance.  They  probably  arise  in  conse- 
quence of  repeated  hypersemia  of  low  grades,  of  venous  hyperemia, 
and  of  those  conditions  indefinitely  known  as  chronic  inflammations. 
Their  association  with  these  conditions,  however,  is  not  clear  enough 
to  definitely  classify  them  as  the  consequences  of  any  determined 
pathological  condition  of  the  pulp.  While  they  are  unquestionably 
evidences  of  pulp-degeneration,  and  should  be  so  classified,  they  are, 
for  the  sake  of  convenience,  grouped  under  the  head  of  constructive 
changes.  The  fact  that  they  are  degenerations  is  to  be  constantly 
borne  in  mind. 

PULP-XODULES. 

Definition. — Pulp-nodules  (pulp-stones,  nodular  calcifications)  is  the 
name  applied  to  defined  masses  of  calcic  material  occupying  portions 
1  American  System  of  Dentistry,  vol.  i. 


CONSTRUCTIVE  DISEASES  OF  THE  DENTAL  PULP. 


335 


of  the  pulp-chamber  and  causing  displacement  of  the  pulp-sub- 
stance. 

Occurrence. — Wliile  tliese  growths  may  occupy  the  pulp-chambers 
of  teeth  in  which  the  pulp  has  been  the  seat  of  direct  irritation,  their 
occurrence  is  by  no  means  confined  to  such  teeth.  They  are  found,  not 
only  in  teeth  which  have  suffered  abrasion,  erosion,  and  slowly  progress- 
ing caries,  but,  as  pointed  out  by  Black,  they  may,  and  frequently  do, 
form  in  other  teeth  of  the  same  denture  which  are  not  directly  involved 
in  the  irritation.  This  investigator  notes  that  irritation  of  the  pulp 
of  one  tooth  of  a  denture  very  frequently  causes  a  general  hvperresthe- 
sia  of  the  pulps  of  all  of  the  teeth.  This  is  particularly  notable  in  the 
type  of  persons  classed  as  neuralgic.  It  is  also  common  in  persons  of 
the  gouty  diathesis.  It  should  be  remarked  that  a  general  ])ulp-hvper- 
sesthesia  is  frequently  the  precursor  of  an  acute  outbreak  of  gout  in 
such  persons.  Nodules  are  found  much  more  frequently  in  the  teeth  of 
middle-aged  persons  than  in  those  of  youth,  although  they  may  be  pres- 
ent as  early  as  the  fifteenth  year.  They  occur  more  frequenth'  multiple 
than  single.  Some  of  the  larger  nodules  are  evidently  formed  by  the 
coalescence  of  smaller  ones. 

Pathology  and  Morbid  Anatomy. — The  structure  of  pulp-nodules 
does  not  resemble  that  of  dentin  ;  they  possess  about  the  same  degree 

Fig.  267. 


Section  of  a  pulp-nodule,  showing  many  calco-spherites,  as  pointed  out  by  a,  a.    (Black.) 

of  translucency  and  hardness.  Outwardly  they  may  assume  almost  any 
form  ;  they  range  in  size  from  minute  bodies  to  a  size  sufficient  to 
almost  obliterate  the  pulp  (Fig.  265). 

A  section  of  a  nodule  exhibits  the  presence  of  a  number  of  concen- 
trically laminated  bodies,  recognizable  as  hardened  calco-spherites. 
Black  found  them  "  to  rarely  make  up  any  considerable  portion  of  the 


336 


CONSTRUCTIVE  DISEASES. 


bulk  of  the  nodule.     The  remainder  of  the  nodule  is  made  up  of  struc- 
tureless dentinal  matter. 

He  also  found  deposits  in  the  pulp  which  throw  light  upon  the  possible 
origin  of  nodules  in  some  cases,  and  to  some  extent  upon  the  conditions 
under  which  they  may  be  formed  (Fig.  268).     In  the  pulp  of  a  second 

Fig.  268. 


Deposit  of  calco-globulin  within  the  tissues  of  an  inflamed  pulp.    (Black.) 

molar  of  a  girl  aged  fifteen,  in  which  there  had  been  decided  subjective 
evidences  of  pulpitis  recurring  at  intervals,  for  a  period  of  two  months, 
he  found  a  mass  representing  a  pulp-nodule  in  its  soft  state.  "About 
one-half  of  the  coronal  portion  of  the  pulp  was  involved  in  the  inflam- 
mation ;  lying  a  little  inside  of  the  layer  of  odontoblasts  were  several 
masses  similar  to  Fig.  268,  having  globular  forms  in  their  mass  or 
attached  to  their  margins.  The  globular  bodies  present  the  laminated 
appearance  of  calco-spherites."  These  masses  may  in  all  probability 
be  interpreted  as  intermediate  products  in  the  formation  of  nodules ; 
they  have  not  yet  become  calcified.  The  conditions  of  calcification  in 
enamel  and  dentin  are  not  definitely  known  (Chapter  VII.),  so  that  the 
mode  of  calcification  in  pulp-nodules  is  also  unknown.  Black  suggests, 
following  the  experiments  of  Rainey,  Ord,  and  Harting,  that  the  chemi- 
cal conditions  for  the  formation  of  calco-spherites  appear  to  be  a  solu- 
tion of  albumin,  calcium  salts,  and  an  excess  of  carbon  dioxid ;  these 
conditions  are  realized  when  there  is  an  excess  of  venous  blood  in 
semi-stagnation,  the  conditions  which  exist  in  varicose  veins,  a  patho- 
logical state  in  which  concretions  (phleboliths)  appear  in  the  veins. 
"  When  a  venous  thrombus  is  but  partially  replaced  by  connective 
tissue  the  remainder  of  it  may  become  calcified,  forming  phleboliths.^ 
While  this  may  and  no  doubt  does  serve  to  explain  calcareous  degen- 
erations, it  fails  to  explain  the  formation  of  pulp-nodules,  which  exist 
in  teeth  which  have  never  been  the  seat  of  caries,  and  whose  pulps 
exhibit  no  structural  change  other  than  the  presence  of  nodules.  More- 
over, the  presence  of  hardened  calco-spherites,  and  even  an  amorphous 

^  Ziegler. 


CONSTRUCTIVE  DISEASES  OF  THE  DENTAL  PULP.  337 

calcified,  translucent  mass,  implies  secretion  rather  than  chemical  pre- 
cipitation. They  are,  however,  not  to  be  classed  as  secondary  dentin,  be- 
cause they  lack  the  distinguishinjii;  feature  of  dentin — dentinal  tubules. 

Symptoms. — Multiple  nodules  may  exist  in  a  dental  pulp  and  give 
rise  to  no  evident  symptoms  whatever,  as  is  shown  by  their  presence  in 
extracted  teeth,  many  of  them  free  from  caries,  and  in  which  there 
was  no  history  of  pain.  On  the  contrary,  the  pulp  of  a  tooth  may 
be  the  seat  of  intractable  pain  without  a  depth  of  carious  invasion 
which  would  lead  to  the  inference  of  acute  pulp-disease ;  and  relief 
only  be  secured  through  devitalization  of  the  pulp,  which  upon  exami- 
nation may  reveal  a  small  pulp-nodule. 

The  symptoms  attendant  upon  the  presence  of  nodules,  so  far  as 
they  can  be  made  out,  appear  to  be  of  two  types — those  associated  with 
small  and  those  with  extensive  deposits.  Reflex  pain  is  the  common 
associate  of  both. 

Small  Deposits. — While  it  is  true  that  pulp-nodules  exist  in  appar- 
ently sound  teeth  Avithout  inducing  pain,  yet  the  pulps  of  teeth  contain- 
ing them  become  excessively  hypersesthetic  under  what  are  ordinarily 
mild  sources  of  irritation.  This  is  manifested,  first,  through  the  con- 
tents of  the  dentinal  tubuli ;  the  dentin  becomes  exquisitely  sensitive, 
and  cool  water  directed  into  a  shallow  cavity  produces  a  paroxysmal 
and  excruciatingly  painful  response  from  the  pulp.  In  the  absence  of 
direct,  extraneous  irritation  of  the  pulp,  the  dental  symptoms  may  be 
absent,  but  a  persistent  neuralgia  may  be  located  at  some  distant  point. 
Pain  in  the  ear  is  a  frequent  symptom.  Occasionally  an  obstinate  scalp 
neuralgia,  with  the  existence  of  a  hypersesthetic  spot,  appears.  Pain  in 
the  eye,  with  tenderness  over  the  supra-orbital  foramen,  is  also  common. 
The  pain  may  be  recurrent  or  persistent.  If,  in  the  absence  of  a  more 
probable  explanation  of  the  pain,  a  pulp-nodule  be  suspected,  and 
arsenical  applications  be  made  to  devitalize  the  pulp,  it  is  found  that 
not  only  is  intense  pain  caused,  but  examination  after  from  forty-eight 
to  seventy-two  hours  shows  the  pulp  to  be  still  vital  and  hypersensitive  ; 
and  in,  order  to  effect  its  destruction  repeated  applications  and  large 
doses  of  arsenic  must  be  used. 

Large  Deposits. — In  extensive  deposits  of  pulp-nodules  the  dentin 
may  be  almost  devoid  of  sensation,  and  applications  of  heat  or  cold, 
even  in  large  cavities,  may  be  followed  by  delayed  and  faint  pulp- 
response.  Such  cases,  however,  commonly  give  a  history  of  reflex  neu- 
ralgia and  vague  dental  pains  extending  over  a  period,  it  may  be,  of 
years.  Their  diagnosis  may  only  be  made  after  devitalization  of 
the  pulp  and  the  finding  of  the  nodules  in  the  pulp-chamber  or  pulp- 
substance.  The  tardy  action  of  arsenic  is  also  observed  in  these  cases, 
it  being  frequently  necessary  to  devitalize  the  pulp  piecemeal. 

22 


338 


CONSTRUCTIVE  DISEASES. 


Treatment. — When  pulp-nodules  have  been  diagnosed  as  the 
probable  source  of  dental  pain  or  of  reflex  neuralgia,  the  therapeutic 
indication  is  the  devitalization  and  removal  of  the  pulp.  The  first 
arsenical  application  should  contain  a  much  greater  amount  of  cocain 
than  arsenic.  In  forty-eight  hours  a  stronger  paste  may  be  applied.  In 
the  more  obstinate  cases,  it  may  be  one  or  two  weeks  before  devitalization 
is  complete.  Uncomfortable  symptoms  referred  to  the  teeth  may  persist 
for  some  time  subsequent  to  devitalization  and  thorough  removal  of 
the  pulp.  Evidences  of  pericemental  disturbance,  tenderness  upon  per- 
cussion, may  appear.  The  uncomfortable  symptoms  disappear,  as  a 
rule,  if  a  saturated  solution  of  menthol  in  chloroform  be  pumped  in  the 
canals,  the  cavity  sealed,  and  the  gum  at  a  distance  from  the  teeth  be 
painted  with  tincture  of  iodin. 


CALCIFIC   DEGENEEATIONS   OF    THE   PULP. 

Calcific  degenerations  of  the  pulp  are  of  two  types  :  one  occurs 
as  a  sequel  of  the  degenerative  changes  of  age — atheroma ;  the  other, 
as  calcic  deposits  in  tissues  of  the  pulp  which  have  been  the  seat  of 
acute  or  subacute  vascular  derangements.     Calcareous  degeneration,  as 

Fig.  269. 


A,  diagram  of  a  section  of  a  central  incisor,  with  a  proximaldecay  at  a  which  seems  to  have  pene- 
trated the  original  pulp-chamber,  but  the  opening  is  closed  by  calcification  at  6  ;  c  marks  the 
position  of  a  detached  mass  of  calcific  material  that  was  lost  in  mounting  the  section.  B, 
shows  the  appearance  of  the  calcific  deposit ;  this  seems  to  be  a  calcification  of  inflamed  or 
cicatricial  tissue  ;  at  a  there  is  the  appearance  of  a  bloodvessel ;  b,  pulp.    (Black.) 

pointed  out  in  Chapter  lY.,  has  as  a  precursor  other  degenerative 
changes  ;  it  is,  in  fact,  a  deposition  of  calcic  material,  calcium  and  mag- 
nesium phosphate  and  calcium  carbonate,  in  already  degenerated  tissues. 
Causes. — The  causes  of  calcareous  degenerations  of  the  pulp  are 
therefore  in  previous  diseases  of  the  pulp  which  have  induced  degen- 


CONSTRUCTIVE  DISEASES  OF  THE  DENTAL  PULP. 


339 


erative  changes  in  the  pulp-tissue.    Prominent  among  these  Black  found 
grades  of  pulp-inflammation,  of  hypersemia  (Fig.  269). 

Patholog-y  and  Morbid  Anatomy. — The  calcic  material,  unlike  the 
cases  of  nodular  calcification,  incloses  the  anatomical  elements  of  a  pulp 
in  process  of  degeneration  in  a  mass  produced  by  deposition,  not  secre- 
tion. In  the  root-portions  of  pulps  in  which  fibrous  elements  have 
become  pronounced  the  calcification  may  be  tubular  or  cylindrical  in 
character,  the  nature  of  the  calcareous  masses  being  apparently  a  depo- 
sition about  and  along  the  fibres  (Fig.  270). 

Fig.  270. 


A,  outline  of  a  lower  molar,  with  a  large  carious  cavity  at  a ;  b,  pulp-chamber ;  the  shaded  portion, 
e,  was  occupied  by  cylindrical  calcifications.    B,  cylindrical  calcifications.    (X  100.)    (Black.) 


OSTEODENTIN. 

Tomes  ^  states  that  secondary  dentinal  deposits  may  assume  the 
character  of  osteodentin,  a  form  of  dentin  found  in  the  teeth  of  some 
animals,  in  which  the  tissue  presents  combined  characters  of  both  bone 
and  dentin,  citing  the  example  also  that  elephant  tusks  are  frequently 
repaired  with  osteodentin  after  injury.  The  specimen  illustrated  (Fig. 
271)  was  taken  from  a  case  in  which  the  coronal  portion  of  the  pulp- 
chamber  was  almost  obliterated  by  a  deposit  of  secondary  dentin.  It  is 
difficult  to  conceive  the  origin  of  the  osteoblasts  in  this  case  ;  the  evi- 
dences of  former  odontoblasts  are  plain  ;  but  whether  odontoblasts  under 
altered  conditions  have  become  osteoblasts  is  a  matter  of  conjecture. 

To  recapitulate,  there  appear  to  be  at  least  three  distinct  types  of 
calcic  formations  in  the  pulp-chamber.  First,  secondary  dentin,  in 
which  the  odontoblasts  recede  from  their  original  positions  in  conse- 
quence of  a  new  formation  of  dentinal  material,  leaving  behind  them 
processes  which  give  the  new  formation  the  character  of  dentin.  The 
process,  in  the  main,  is  associated  with  a  mild  and  continued  irritation 
leading  to  a  continued  hypernutrition.  After  a  period  the  physiological 
activity  of  the  odontoblasts  ceases  and  they  undergo  atrophy.     The 

^  Dental  Anatomy. 


340 


CONSTRUCTIVE  DISEASES. 


second  class  of  cases,  nodular  deposits,  possess  the  physical  and  chem- 
ical properties  of  dentin  without  its  anatomical  characteristics ;  it  is 
dentinal  substance,  but  not  dentin  histologically  ;  hence  it  differs  from 
dentin  in  not  being  formed  through  the  agency  of  odontoblasts ;  it  is 


Fig.  271. 


Osteodentin:  ^4,  outline  of  incisor,  showing  a  narrowing  of  the  root-canal  at  &  by  a  deposit  of 
osteodentin.  B,  illustration  of  the  tissue :  a,  primary  dentin ;  '6,  line  of  the  beginning  of  a 
growth  of  secondary  dentin ;  c,  secondary  dentin ;  d,  layer  of  granular  matter :  e,  osteo- 
dentin ;  this  has  the  lacunse  at  g  and  dentinal  tubes  at  k;  f  seems  to  be  the  surface  of  the 
osseous  deposit ;  i,  irregular  crystalline  deposits ;  h,  the  pulp-chamber.    X  350.    (Black.) 

the  product  of  secretory  instead  of  formative  action.  Whether  nodular 
deposits  are  first  formed  as  a  soft  mass,  and  subsequently  calcified,  is 
not  known.  They  appear  in  general  to  be  the  result  of  marked  and 
irregular  irritation  of  the  pulp.  The  third  form  are  calcareous  depo- 
sitions about  anatomically  degenerated  tissue  occurring  as  a  secondary 
process  to  degeneration  and  always  indicating  the  near  death  of  the 
pulp. 


CHAPTER  XVIII. 

DESTRUCTIVE  DISEASES  OF  THE  DENTAL  PULP. 

The  next  class  of  pulp-diseases  are  those  of  an  acute  character, 

although  chronic  diseases  may  arise  as  sequelse  of  the  original  conditions. 

They  are  essentially  destructive  in  character  and  attended  by  prompt 

degeneration  of  the  pulp-tissues.     The  most  important  clinically  are 

those  havine;  an  evident  association  with  disorders  of  the  bloodvessels 

of  the  pulp. 

Hyperemia  of  the  Pulp. 

Hypersemia  of  the  pulp  is  an  excess  of  blood  in  the  more  or  less 
dilated  vessels  of  that  organ.  It  is  of  two  forms,  active  or  arterial 
hyperemia,  and  venous  or  passive  hypera^mia  or  congestion.  These 
two  classes  diifer  in  their  probable  direct  causations  and  in  effects. 

ACTIVE    HYPER.EMIA    OF    THE   PULP. 

Definition. — Active  or  arterial  hypersemia  of  the  pulp  is  an  excess 
of  blood  in  the  dilated  arteries  and  capillaries  of  the  pulp. 

Causes. — The  most  common  cause  of  active  hypersemia  of  the  pulp 
is  a  lessening  of  the  non-conducting  covering  of  the  organ,  enamel  and 
dentin,  leading  to  an  increased  response  and  continued  irritation  of  the 
pulp  through  thermal  stimuli.  A  similar  condition  consists  in  the 
presence  of  large  metallic  fillings  in  close  proximity  to  the  pulj),  through 
which  abnormal  thermal  stimuli  are  received.  Fillings  through  which 
prompt  pulp-response  to  thermal  changes  are  felt  are  a  direct  menace 
to  the  continued  health  of  the  pulp.  "  The  vigorous  use  of  sandpaper 
disks  in  finishing  large  fillings  may  and  does  precipitate  an  attack  of 
pulp  hypersemia."  ^  The  loss  of  tooth-substance  mentioned  may  be 
either  through  abrasion,  erosion,  or  caries.  The  condition  frequently 
occurs  without  direct  exposure  of  the  dental  pulp. 

Symptoms. — When  the  pulp  has  lost  much  of  its  protective  cover- 
ing, its  response  to  thermal  change  becomes  increased.  So  long  as  a 
quick,  sharp  pain  is  produced  by  contact  with  cold  or  hot  substances, 
ceasing  immediately,  and  only  reappearing  in  response  to  direct  stimuli, 
no  serious  vascular  disturbance  is  inferred ;  but  when  paroxysms  of 
sharp  pain  lasting  from  many  minutes  to  hours  follow  upon  an  applica- 
tion of  cold  to  a  carious  cavity,  an  unbroken  enamel-surface,  a  filling, 

'  Black. 

341 


342  DESTRUCTIVE  DISEASES. 

or  an  area  of  erosion  or  abrasion,  a  disturbance  of  the  vessels  of  the 
pulp  is  suspected.  The  pains,  in  the  absence  of  direct  and  intentional 
irritation,  are,  as  a  rule,  but  vaguely  located.  It  is  common  to  have 
the  pain  referred  to  somewhere  in  the  region  of  the  aifected  tooth ; 
rarely  to  the  tooth  itself.  It  is  not  at  all  unusual  to  have  the  patient 
refer  the  pain  to  an  entirely  sound  tooth  at  a  distance  from  the  one 
affected  ;  a  tooth  in  the  opposite  jaw  may  be  declared  to  be  the  seat  of 
pain,  and  it  may  require  the  application  of  the  thermal  test  to  the 
offending  pulp  to  convince  the  patient  of  the  error  of  location. 

For  some  period  previous  to,  and  it  may  be  after,  an  attack  of  acute 
paroxysmal  pain,  trigeminal  neuralgia  of  the  side  may  be  complained  of. 
A  favorite  location  of  this  pain  is  in  the  ear.  As  a  rule,  when  an  upper 
tooth  is  affected  the  pain  is  located  in  the  superior  maxillary  division  of 
the  fifth  nerve  ;  if  a  lower,  to  the  inferior  maxillary  division.  The 
pain  varies  in  intensity  from  a  vague  uneasiness  to  an  acute  neuralgic 
attack,  with  tender  spots  over  the  emergence  of  the  nerve-tracks,  at  the 
supra-  and  infra-orbital,  and  mental  foramina.  The  neuralgic  pains  are 
not  always  constant ;  they  may  disappear  from  the  second  or  third 
division  of  the  fifth  nerve  and  appear  in  the  first. 

The  proof  of  the  direct  connection  between  the  pulp-pain  and  the 
neuralgia  may  in  some  cases  be  clearly  made  out  by  the  thermal  test. 
When  a  jet  of  cool  water  is  directed  against  the  tooth  whose  pulp  is 
affected,  it  may  produce,  in  addition  to  a  local  pain,  an  aggravation  of 
the  neuralgic  pains. 

Patholog-y  and  Morbid  Anatomy. — The  one  distinctive  and  charac- 
teristic anatomical  condition  associated  with  active  hypersemia  is  an  irreg- 
ular dilatation  of  the  vessels  of  the  pulp.^  Fig.  272  represents  a  section 
of  the  pulp  of  a  tooth  extracted  during  a  paroxysm  of  acute  pain — 
"  acute  paroxysms  of  pain  lasting  for  an  hour  or  more  were  occasionally 
occurring  in  consequence  of  very  trivial  changes  of  temperature ;  the 
condition  had  existed  for  several  weeks."  In  some  cases  of  a  similar 
character — i.  e.,  presenting  the  same  symptoms,  but  extracted  during  an 
interval  of  quiet — nothing  remarkable  is  presented ;  the  veins  of  the 
bulb  may  be  abnormally  large  and  contain  more  blood  than  usual, 
while  the  arteries  will  be  almost  or  quite  empty  and  the  injection  of 
the  capillary  system  wanting ;  that  is,  the  affected  arteries  have  recov- 
ered their  calibre,  if  not  their  tone.  Black  found  the  varicose  enlarge- 
ment of  vessels  so  common  (Fig.  273)  as  to  be  a  characteristic.  Salter^ 
first  called  attention  to  the  dilatation  of  veins  into  ampullae,  describing 
them  in  connection  with  ulceration  of  the  pulp,  as  due  to  engorgement 
and  overtension  of  the  veins. 

The  most  rational  explanation  of  the  dilatation  of  the  vessels  is  that 

^  Black,  American  System  of  Dentistry.  ^  Dental  Pathology  and  Surgery. 


HYPEREMIA    OF  THE  PULP. 


343 


it  is  an  irregular  paralysis  of  vessel-walls — /.  c,  of  vasomotor  nerves. 
Whether  the  more  usual  painful  responses  of  the  pulp  to  thermal  stim- 

FiG.  272. 

h 


'1  ■■Wi«, 


Hyperfemia  of  the  dental  pulp,  showing  the  natural  injection  of  the  vessels  :  a,  a.  membrana  ehoris, 
or  layer  of  odonoblasts ;  6,  6,  b,  b,  vessels  distended  with  blood ;  c,  c,  c,  c,  points  from  which  the 
blood  has  fallen  in  handling  the  section.    (Black.) 

uli  are  due  to  the  stimulation  of  vasodilator  fibres,  which  causes  a  transi- 
tory hyperaemia,  is  a  matter  of  doubt ;  but  the  pathological  conditions 

Fig.  273, 


Dilated  bloodvessels  from  the  dental  pulp  in  hypersemia,  from  tooth  extracted  during  a  paroxysm 

of  intense  pain.    (Black.) 

noted  in  pronounced  hypersemia  signify  a  paralysis  of  vasoconstrictor 
fibres.      Subjected  to  repeated  over-stimulation,  they  become  inaetive 


344  DESTRUCTIVE  DISEASES. 

and  the  vessel-walls  yield  to  the  pressure  of  the  blood-column.  Black's 
researches  indicate  that  the  vessel-^yalls  may  recover  their  tone  and  the 
vasoconstrictor  nerves  their  functional  activity  after  paralysis. 

Diag-nosis  and  Prognosis. — Diagnosis  of  hypersemia  of  the  pulp  is 
made  through  ol^servance  of  a  combination  of  signs  and  symptoms.  The 
symptoms  leading  to  its  detection  are  paroxysms  of  pain  induced  by 
thermal  stimuli,  and  a  history  of  pain  in  the  region  in  which  this  re- 
sponse is  elicited.  The  signs  of  the  condition  in  the  order  of  their 
importance  and  frequency  are  carious  cavities,  the  presence  of  large 
metallic  fillings,  deep  erosions  or  abrasions,  and,  again,  fractured 
enamel  exposing  the  dentin,  or  metallic  crowns  on  teeth  containing 
vital  pulps. 

As  a  rule,  the  case  presents  a  history  of  paroxysmal  pain  for  a  period  ; 
either  a  single  or  several  attacks.  While,  usually,  pulp  hyperemia 
is  only  associated  with  deep  cavities  of  decay,  it  is  occasionally  found  as 
an  accompaniment  of  limited  and  comparatively  superficial  dentin 
exposures.  The  water  used  in  testing  the  pulp-reaction  should  not  be 
at  a  lower  temperature  than  60°  F.,  and  then  be  applied  only  in  drops, 
never  in  a  forcible  stream.  A  normal  pulp  will  rarely  respond  pain- 
fully to  a  few  drops  of  water  at  the  temperature  named,  flowed  into  a 
cavity  ;  but  a  hypersemic  pulp  will  almost  invariably  respond  vigorously. 
As  a  rule,  a  current  of  air  from  a  chip  blower  is  a  test  of  sufficient 
severity. 

In  the  absence  of  a  carious  cavity  the  source  of  the  pain  is  to  be 
sought  in  large  fillings,  testing  each  tooth  by  dropping  cool  water  on 
the  filling ;  in  cases  of  erosion  or  abrasion  the  test  is  made  upon  the 
exposed  dentin.  The  tooth  which  responds  in  a  quick  paroxysm  of 
intense  pain,  passing  away  slowly,  is  diagnosed  as  the  seat  of  pulp 
hyperemia. 

The  prognosis  of  this  condition  is  important  as  determining  the  course 
of  treatment.  Governed  by  clinical  experience,  many  operators  invari- 
ably devitalize  and  remove  a  pulp  which  has  been  the  seat  of  more  than 
one  attack  of  paroxysmal  pain.  Others  attempt  the  conservative  treat- 
ment of  the  organ  even  when  it  has  been  judged  from  the  symptoms 
the  seat  of  repeated  hyperemia,  and  report  that  success  usually  attends 
the  effort,  provided  due  precautions  have  been  taken  as  to  antisepsis, 
the  character  of  pulp-cupping,  and  to  non-conductivity  of  the  pulp- 
covering. 

Black  ^  has  shown  the  capability  of  the  pulp  to  recover  from  repeated 
hypersemia  ;  that  is,  as  regards  the  condition  of  its  bloodvessels  ;  and 
the  records  of  observers  (notal^ly  Louis  Jack")  show  that  after  years 

^  American  System  of  Dentistry,  vol.  i. 

*  American  Text-book  of  Operative  Dentistry. 


HYPEREMIA   OF  THE  PULP.  345 

the  pulp  responds  normally  to  thermal  stimuli,  proving  its  continued 
vitality,  aye  more,  its  health.  It  is  possible  that  those  who  condemn 
the  attempts  at  conservation  of  the  pulp  after  hypersemia  have  con- 
founded this  vascular  condition  with  serious  degenerative  changes. 
Properly  treated,  the  prognosis  of  active  hyperemia  of  the  pulp  is, 
upon  the  w^hole,  favorable. 

Treatment. — The  therapeutic  principles  involved  in  the  treatment 
of  this  condition  are  :  the  removal  of  the  source  of  irritation  and  the 
securing  of  physiological  rest ;  the  latter  can  only  be  secured  through 
the  removal  of  the  former.  The  treatment  is  directed  toward  imme- 
diate relief  of  the  existing  condition  and  the  prevention  of  its  re-occur- 
rence. If  a  carious  cavity  exist,  it  is  to  be  freed  from  debris  ;  and  the 
grosser  portions  of  the  carious  dentin  are  removed  ;  the  pulp,  if  unex- 
posed, is  to  have  the  layer  of  softened  dentin  covering  it  left  unremoved. 
Sedative  agents  are  imperatively  called  for,  that  most  commonly  em- 
ployed being  carbolic  acid.  This  agent  is,  however,  discountenanced 
by  some  practitioners  on  account  of  the  possible  deleterious  effect  it 
may  have  on  the  pulp  ;  this  ol)jection  is  not  generally  sustained.  The 
essential  oils  are  perhaps  the  most  effective  agents  for  use  in  this  con- 
nection. The  oils  of  cloves,  of  gaultheria,  cinnamon,  thyme,  and 
menthol  are  all  extensively  used  and  are  all  effective.  Of  these,  thymol 
acts  most  promptly  ;  a  saturated  solution  in  alcohol  being  used,  sealed 
in  the  cavity  Avith  temporary  stopping.  It  is,  in  addition,  a  germicide 
of  sufficient  activity  to  sterilize  the  dentin  covering  the  pulp.  The 
essential  oils  act  as  sedatives,  and  the  non-conducting  temporary  stopping 
secures  rest  by  preventing  the  conduction  of  thermal  stimuli.  In  from 
twenty -four  to  forty-eight  hours  the  tooth  is  placed  under  the  rubber-dam, 
and  excavated  (see  Chapter  XVI.);  its  walls  are  varnished,  and  over 
the  wall  nearest  the  pulp  a  disk  of  softened  gutta-percha  is  laid.  Over 
this  zinc-phosphate  paste  is  flowed.  It  is  usual  to  complete  such  fillings 
with  zinc  phosphate  or  gutta-percha,  to  remain  for  six  months  or  a  year. 
The  conductivity  of  zinc  phosphate  is  too  high  to  be  used  as  the  sole 
material  over  pulps  which  have  been  the  seat  of  hypera?mia.  If  the 
pulp  be  exposed,  it  is  capped  as  described  in  Chapter  XVI. 

In  cases  of  abrasion  or  erosion  carbolic  acid  is  applied  ;  an  excava- 
tion having  a  retentive  form  is  made,  which  is  varnished  and  filled  with 
zinc  phosphate.  A  tooth  containing  a  large  metallic  filling  must  have 
the  filling  removed  and  after  reducing  the  hyperjemia  a  non-conducting 
layer  must  be  placed  between  the  pulp  and  the  filling.  The  precaution 
should  always  be  taken,  when  the  pulps  of  teeth  in  which  cavities  have 
been  prepared  respond  unduly  to  the  temperature-test,  to  cover  the 
dentinal  walls  with  a  layer  of  non-conducting  material.  In  the  absence 
of  this  precaution  the  constant  overstimulation  of  the  pulp  by  thermal 


346 


DESTRUCTIVE  DISEASES. 


impulses  conducted  through  the  metallic  filling,  may  at  any  time  result 
in  hypersemia. 

Idiopathic  hypersemia  occasionally  affects  teeth  in  which  there  is  no 
loss  of  enamel  or  dentin  ;  and  when  this  condition  occurs,  it  leads  to 
suspicion  that  the  pulp  is  the  seat  of  nodular  deposits.  Such  teeth  are 
to  be  dried,  heavily  varnished,  and  wedged  upon  both  sides  for  twenty- 
four  hours,  until  a  gutta-percha  cap  can  be  fitted  to  them  completely 
enclosing  the  crown.  The  cap  is  to  remain  and  to  be  renewed  until  the 
tooth  responds  normally  to  the  temperature-test. 

VENOUS    HYPERiEMIA    OF    THE    PULP. 

Pathology  and  Morbid  Anatomy. — Considering  the  mode  of  vas- 
cular supply  to  the  teeth,  arteries  entering  and  veins  leaving  the  tooth 
by  a  rigid  and  constricted  channel,  it  is  evident  that  if  the  arteries  be 
dilated   the  veins   must   suffer  more    or   less   compression,  causing  a 

Fig.  274. 


Section  of  hypersemic  pulp,  showing  aneurismal  dilatation  of  the  vessels,  extravasations  of  blood, 
and  red  blood-disks  escaped  apparently  by  diapedesis :  a,  o,  dilated  vessels;  6,  6,  6,  extrava- 
sated  blood.  Besides  this,  red  blood-disks  are  plentifully  distributed  everywhere  in  the 
neighborhood  of  the  veins.    The  tooth  was  extracted  during  a  paroxysm  of  pain.    (Black.) 


-I.  6.,  venous  or 


mechanical   obstruction   to   the   return   of   the   blood- 
mechanical  congestion  is  likely  to  be  established. 

In  teeth  having  more  than  one  root  the  venous  engorgement  may  be 


HYPER.EMIA    OF  THE  PULP.  347 

lessened  by  escape  of  blood  tliroiigh  a  second  root.  In  single-rooted 
teeth  conijestion  mud  be  established  Avhen  the  arterv  or  arteries  are 
affected  near  the  apical  foramen.  It  is  inferred  that  in  the  foregoing 
conditions  described  the  interference  with  venous  return  has  been  but 
partial. 

The  condition  raises  the  tension  of  the  blood  in  the  capillaries  and 
minute  veins,  and  produces  stagnation  in  the  emergent  veins  ;  there  is 
mechanical  stagnation  (Fig.  274).  It  is  evident  that  if  this  condition 
continue  for  a  length  of  time  that  thrombosis  must  occur  in  one  or 
more  veins. 

Black  ^  has  described  sequelse  of  active  hyperaemia  which  appear  to 
correspond  Avith  those  conditions.  Extravasations  of  red  blood-cor- 
puscles occur  in  the  tissues.  CEdema,  the  usual  accompaniment  of 
venous  congestion,  cannot  occur,  as  there  is  no  room  for  exudations. 
The  condition,  corpuscular  extravasation,  corresponds  with  that  of 
hemorrhagic  infarct — the  degeneration  and  death  of  more  or  less  pulp- 
tissue  are  inevitable.  Black  suggests  that,  no  doubt,  many  cases  of 
pulp  death  en  masse  are  due  to  the  condition  of  general  infarction. 
The  force  of  this  suo-o-estion  is  evident  when  ii  is  remembered  that  the 
arteries  to  single-rooted  teeth  are  virtually  terminal  arteries.  If  the 
inflirction  be  incomplete,  more  or  less  inflammation  of  the  pulp  is 
almost  sure  to  supervene.  Disintegration  of  the  red  corpuscles  may 
occur  and  the  coloring-matter  of  the  corpuscles  may  be  diifused  through 
the  dentin,  giving  it  a  pink  discoloration.  The  infiltrated  dentin  may 
then  become  progressively  discolored  through  the  characteristic  changes 
of  color  noted  in  connection  with  gradually  decomposing  hsemoglobin — 
becoming  brown,  blue,  and  finally  blue-black. 

Symptoms. — The  symptoms  of  this  condition,  in  the  absence  of 
definite  data,  can  only  be  inferential.  When  the  paroxysms  of  pain 
are  continuous,  instead  of  temporary — that  is,  when  the  pain,  instead 
of  temporarily  subsiding,  maintains  a  constant  intensity  for  hours,  and 
does  not  respond  promptly  to  therapeusis,  and  is  accompanied  by  a  sense 
of  fulness  rather  than  sharp  agony,  a  condition  of  serious  venous  con- 
o-estion  is  inferred.  The  case  from  which  the  illustration  is  taken  had 
been  the  seat  of  intense  paroxysmal  pain  for  some  hours. 

Prognosis. — Perfect  recovery  from  this  condition  is  extremely 
doubtful,  so  that  if  the  pulp  be  not  intentionally  devitalized  and 
removed,  it  will  undergo  degenerative  changes.  The  fact  that  pulps 
have  remained  alive  for  years,  after  having  been  the  seat  of  marked 
congestion,  scarcely  warrants  the  attempt  to  save  so  seriously  crippled 
an  organ  in  all  cases. 

Treatment. — Considering  the  nature  of  the  anatomical  changes,  it  is 

'  American  System  of  Dentistry,  vol.  i. 


348  DESTRUCTIVE  DISEASES. 

doubtful  whether  the  pulp  can  ever  fully  recover ;  so  that  devitalization  and 
extirpation  are  asually  practised  in  these  cases.  Before  this  is  attempted 
or  before  any  attempt  is  made  at  permanent  treatment,  relief  is  demanded 
from  the  pain.  After  washing  out  the  cavity  with  warm  alkaline  solu- 
tions, a  warm  solution  of  phenol  sodique  is  admirable ;  the  cavity  is 
cleansed  of  softened  dentin,  usually  exposing  the  pulp  in  the  operation. 
This  organ,  instead  of  being  pink,  is  seen  to  have  a  purjDlish  hue,  and 
immediately  protrudes  through  the  opening  of  exposure.  If  the  surface 
of  the  pulp  and  the  cavity-walls  be  touched  with  a  strong  antiseptic, 
such  as  a  solution  of  hydronaphthol  in  alcohol,  and  a  very  sharp  probe 
which  has  been  dipped  in  carbolic  acid  be  used  to  delicately  punc- 
ture the  pulp,  there  is  an  immediate  and  free  flow  of  blood  which  is 
permitted  to  continue  for  some  minutes,  relieving  the  vascular  engorge- 
ment. In  five  minutes  the  cavity  is  syringed  wdth  a  warm  antiseptic 
solution  (phenol  sodique  will  answer),  and  a  pellet  of  cotton  containing  a 
saturated  solution  of  menthol  in  chloroform  may  be  laid  over  the  pulp,  and 
retained  in  place  by  another  pellet  of  cotton.  This  application  is  usually 
more  effective  than  even  a  saturated  solution  of  cocain  hydrochlorid  in 
glycerin.  The  following  day  an  arsenical  application  may  be  made. 
If  the  pain  subside,  and  the  pulp  remain  quiet  for  a  week  under  a 
temporary  stopping,  some  operators  have  advocated  pulp-capping  even 
in  this  condition. 

Inflammation  of  the  Dental  Pulp,  or  Pulpitis. 

Definition. — Inflammation,  as  pointed  out  in  Chapter  IV.,  is  a  pro- 
cess to  be  sharply  differentiated  from  that  of  hyperaemia.  It  is  entirely 
separate  and  distinct.  While  several  of  the  phenomena  of  arterial 
hyperaemia  are  present  in  inflammation,  they  constitute  but  a  part  of  the 
process.  The  essential  feature  of  inflammation  is  the  peculiar  aggrega- 
tion and  diapedesis  of  the  white  blood-corpuscles.  Hyperaemia,  no 
matter  of  what  grade  or  variety,  rarely  exhibits  this  feature,  and  then 
but  slightly,  nor  in  any  degree  does  it  present  the  same  types  of  exuda- 
tion or  of  tissue-change  observed  in  inflammation.  Inflammation  of 
the  dental  pulp  is  a  condition  in  which  the  phenomena  of  the  inflam- 
matory process  (see  Chapter  IV.)  occur  in  the  dental  pulp,  their  course 
Vjeing  modified,  as  in  many  other  tissues  of  the  body,  by  the  peculiar 
anatomical  surroundings. 

Causes. — x^owhere  more  than  in  the  dental  pulp  does  the  force  of 
Metchnikoff's  dictum,  that  all  inflammations  are  bacterial  in  origin, 
seem  to  apply.  While  it  must  be  admitted  that  here  as  elsewhere  the 
vast  majority  of  inflammations  are  bacterial  in  origin,  and  that  the 
theory  of  phagocytosis  is  the  most  inclusive  that  has  yet  been  offered, 
yet  there  are  numerous  conditions  in  which  the  bacterial  origin  has  not 


INFLAMMATION  OF  THE  DENTAL  PULP,   OR  PULPITIS.       349 

been  made  out.  We  may  accept,  however,  that  inflammation  is  essen- 
tially Nature's  method  of  ridding  herself  of  irritants,  and  that  phago- 
cytosis is  the  mechanism  through  which  this  is  accomplished,  and  leave 
the  question  of  the  necessary  association  of  bacteria  mib  Judice. 

Taking  this  position,  inflammations  of  the  dental  pulp  may  be  divided 
into  infective  and  non-infective.  There  are  in  all  probability  other 
irritant  factors,  in  addition  to  those  causing  hyperaemia,  necessary  before 
inflammation  can  result.  The  irritants  relate  to  injuries  either  through 
the  operation  of  physical  forces  or  chemical  agencies.  The  chief  of  the 
physical  forces  is  the  presence  of  foreign  bodies,  either  upon  the  surface 
of  the  pulp  or  in  its  substance.  The  chemical  bodies  are  those  which 
cause  death  of  the  tissues  of  the  pulp,  the  inflammation  being  a  reaction 
representing  an  attempt  of  the  pulp  to  segregate  or  expel  the  dead 
tissue;  or  those  chemical  bodies  produced  by  bacteria  which  attract  the 
white  blood-corpuscles  (positive  chemotaxis). 

Pulpitis  is  classified,  according  to  its  extent,  into  partial  and  com- 
plete ;  according  to  its  duration,  into  acute  and  chronic  ;  according  to  its 
infective  character,  into  purulent  and  non-purulent ;  and,  again,  according 
to  the  character  of  the  degeneration  which  follows  upon  the  inflammatory 
process.  While  pathologically  these  conditions  may  be  clearly  dif- 
ferentiated from  one  another,  they  may  be  reduced  to  more  compact 
groupings  according  to  their  clinical  significance.  For  example,  acute 
pulpitis  is  frequently  infective,  partial  and  purulent ;  chronic  pulpitis 
is  frequently  non-infective,  extensive,  non-purulent,  and  indicative  of 
secondary  degenerations. 

For  the  sake  of  convenience,  pulpitis  will  receive  a  clinical  division 
into  acute  and  chronic.  Some  of  the  chronic  varieties  have  been  de- 
scribed under  the  head  of  degenerations ;  others  are  included  in  the 
suppurative  diseases  of  the  pulp. 

ACUTE    PULPITIS. 

Causes. — The  causes  of  acute  pulpitis  are  direct  and  indirect,  intrin- 
sic and  extrinsic  ;  the  vast  majority  of  cases  being  due  to  extrinsic 
causes.  The  direct  intrinsic  causes  are  hemorrhagic  extravasations  ac- 
companying venous  congestion,  pulp-nodules,  and  injury  of  the  vessels 
at  the  apex  of  the  root.  The  direct  extrinsic  causes  are,  perhaps,  invari- 
ably associated  with  bacterial  invasion,  a  possible  exception  being  the 
pressure  of  filling-material  upon  a  thin  elastic  lamina  of  softened 
dentin,  covering  the  pulp.  The  dental  pulp  is  intolerant  of  the  slight- 
est pressure,  and  rebels  vigorously  when  subjected  to  compression.  It 
is  not  necessary  ^  that  the  pulp  should  be  exposed  to  permit  bacterial 
infection,  and  direct  or  extensive  bacterial  invasion  is  probably  not 
1  Miller,  Dental  Cosmos,  1894. 


350 


DESTRUCTIVE  DISEASES. 


necessary  for  the  production  of  pulpitis.  The  waste-products,  pto- 
mains,  etc.,  of  bacteria  may  find  their  way  to  the  surface  of  the  pulp 
via  the  dentinal  tubuli,  through  a  layer  of  softened  dentin,  and  excite 
inflammation.  It  is  extremely  probable  that  infection  of  the  pulp 
is  an  invariable  consequence  of  its  exposure ;  but  as  a  pulp  may  be 
exposed  without  subjective  evidences  of  hypersemia  or  inflammation,  it 
follows  that  infection  does  not  necessarily  imply  inflammation.  The 
presence  of  a  gross  irritant,  such  as  a  mass  of  food-debris,  vegetable 
seeds,  bread-crumbs,  etc.,  in  contact  with  the  pulp  will  precipitate  an 
acute  inflammation  in  which  bacterial  relations  must  be  taken  into 
consideration. 

"  The  severity  of  the  inflammation  does  not  appear  to  be  proportion- 
ate to  the  number  of  bacteria  present,  and  in  a  highly  inflamed  pulp 
we  may  be  able  to  find  but  few  bacteria.  .  .  .  The  conclusion  seems  to 
be  justified  that  the  inflammation  is  due  to  the  combined  action  of  the 
bacteria  and  their  products  (acids,  ptomains,  etc.)  with  which  the  carious 
dentin  becomes  impregnated."  ^ 

The  general  indirect  intrinsic  cause  of  pulp-inflammation  may  be 
regarded  as  active  hypersemia.  This  condition  furnishes  a  predisposi- 
tion to  active  inflammation,  as  shown  in  Chapter  Y.  Pulpitis  frequently 
occurs  as  a  sequel  to  active  hypersemia,  and  the  causes  producing  this 
condition  must,  therefore,  be  also  regarded  as  the  causes  of  inflamma- 

FiG.  275. 


Inflammation  of  dental  pulp :  a,  a,  normal  cells ;  b,  b,  b,  b,  inflammatory  elements ;  c,  cells  in 
process  of  division  (i^j;  in.).    (Black.) 

tion.     The  use  of  irritating  drugs  in  proximity  to  or  in  contact  with  the 
pulp  may  excite  inflammation. 

Morbid  Anatomy  and  Pathology. — In  determining  the  existence 
of  pulpitis,  no  matter  what  the  symptoms  which  have  presented  or  the 

^  Miller,  Dental  Cosmos,  1894. 


INFLAMMATION  OF  THE  DENTAL  PULP,   OR  PULPITIS.       351 

condition  as  to  exposure,  etc.,  the  microscopic  examination  of  sections 
of  the  aifected  organ  constitutes  the  only  test ;  if  the  changes  character- 
istic of  inflammation  be  absent,  no  matter  what  the  symptoms,  pulpitis 
did  not  exist.  The  essential  feature  of  the  process  is  emigration  of 
the  \vhite  blood-corpuscles  from  the  small  veins  into  the  intercellular 
matrix  of  the  pulp.  At  first  the  inflammatory  elements  (leucocytes) 
are   scattered  through  the  spaces  between  the  pulp-cells  (Fig.  275) ; 

Fig.  276. 


Section  of  dental  pulp,  showing  the  invasion  of  the  inflammatory  process  along  the  course  of  the 
veins— the  diapedesis  of  the  white  blood-corpuscles.    (Black.) 

at  a  later  stage  the  territory  is  occupied  by  round  indifferent  cells  alone. 
The  inflammation  may  be  widespread,  as  shown  in  Fig.  276,  or  may 

Fig.  277. 


Minute  inflammatory  focus  within  the  tissues  of  the  pulp:  a,  n,  arterial  twigs ;  6,  a  nerve-bundle ; 
c,  collection  of  leucocytes.    (Black.) 

be  localized  to  some  portion  of  the  pulp,  as  one  horn  of  a  pulp  ;  Black 
noted  also  inflammatory  action  occurring  in  small  islands  (Fig.  277). 
Swelling  of  the  pulp — exudation — cannot  occur   unless  there  is  a 


352  DESTRUCTIVE  DISEASES. 

break  in  the  wall  of  the  pulp-chamber  through  which  additional  space 
can  be  gained.  Black  has  recorded  that  "  he  found  beneath  the  layer 
of  odontoblasts  in  the  region  of  an  exposure  an  unmistakable  deposit 
of  inflammatory  lymph.  The  case  had  a  history  of  severe  toothache 
for  two  days,  two  weeks  previously.  The  pulp  exhibited  evidences  of 
previous  extravasations  of  blood  from  hypersemia," 

There  is  evidence  that  the  pulp  may  recover  from  attacks  of  inflam- 
mation, and  that  resolution  occurs.  In  some  cases,  as  shown  under  the 
head  of  calcareous  degeneration,  the  tissues  may  become  infiltrated  with 
calcic  material.  In  others,  chronic  degenerative  changes — inflammatory 
degeneration — may  supervene. 

The  cases  thus  far  described  have  been  given  as  non-infective,  simply 
because  their  infective  character  has  not  been  clearly  made  out,  although 
it  is  very  probable  that  they  are  infective. 

Suppuration  of  the  pulp  is  a  common  accompaniment  of  pulp-inflam- 
mation ;  this  being  necessarily  infective,  will  be  described  separately. 

Symptoms. — The  symptoms  of  pulpitis  are  largely  a  matter  of 
inference.  The  existence  of  hypersemia  and  a  general  paretic  state  of 
the  bloodvessels  are  judged  by  symptoms.  Throbbing  pain  referred  to 
the  region  of  some  one  tooth,  and  at  times  referred  definitely  to  the. 
aifected  tooth,  is  regarded  as  a  guiding  symptom.  The  tooth  may 
respond  to  percussion  slightly.  The  pericementum  being  involved  to 
some  extent,  the  throbbing  attendant  upon  the  pulpitis  is  the  reason  for 
the  pain  being  located  at  times  in  the  oiFending  tooth,  instead  of  being 
reflected,  as  usual  in  pulp-affections.  In  other  cases  the  pain  is  referred 
to  far  distant  points  in  the  course,  or  at  points,  of  any  of  the  divisions 
of  the  fifth  nerve.  No  pain  may  be  felt  in  the  tooth  at  all,  and  serious 
disturbances  appear  in  distant  parts,  in  the  eye  or  ear.  The  usual  symp- 
tom, however,  in  addition  to  the  heavy,  throbbing  pain  in  the  tooth,  is  a 
marked  increase  of  suffering  upon  assuming  the  recumbent  position. 
The  paretic  vessels  permit  an  increased  flow  of  blood  into  them  as 
soon  as  its  flow  to  the  tooth  is  favored  by  gravity.  In  the  upright 
position  during  the  day  the  suffering  continues,  although  lessened,  as  a 
dull,  heavy  pain.  The  pulp  responds  to  both  heat  and  cold,  but  more  to 
the  former  than  to  the  latter. 

Diagnosis. — Inflammation  of  the  pulp  is  the  usual  associate  of 
exposure  of  the  organ  whether  marked  symptoms  have  been  present  or 
not.  Its  actual  existence  is  judged  from  presenting  the  local  symptoms 
noted.  A  large  cavity,  with  an  exposed  pulp,  with  dull,  heavy  pain, 
increased  in  the  recumbent  position,  with  little  or  no  response  to  per- 
cussion— pulpitis  is  diagnosed.  If  in  a  tooth  containing  a  large  filling 
these  symptoms  have  been  present,  pulpitis  is  inferred. 

Pulpitis  from  injury  of  the  vessels  at  the  apex  of  the  root  must  be 


INFLAMMATION  OF  THE  DENTAL  PULP,   OR  PULPITIS.      353 

mentioned.  It  may  occur  in  consequence  of  bloAvs,  biting  upon  hard 
substances,  too  rapid  wedging,  the  rapid  movement  of  teeth  in  ortho- 
dontia, and  the  progressive  k)osening  of  teeth  in  pyorrhoea  alveolaris. 
In  these  cases  tlie  pericementum  is  also  affected  and  the  teeth  are  tender 
upon  percussion.  Pain  in  the  teeth  upon  assuming  the  recumbent  posi- 
tion, dull,  heavy  uneasiness  about  the  jaws,  and  inordinate  response 
to  thermal  stimuli,  particularly  to  heat,  point  to  ])ulpitis.  No  doubt 
many  pulps  are  destroyed  by  general  hemorrhagic  infarct  in  these 
cases. 

Prognosis. — While  it  is  undoubtedly  true  that  the  pulps  of  teeth 
which  have  been  the  seat  of  inflammation  may  recover,  that  resolution 
may  occur,  it  is  the  general  experience  that  they  usually  degenerate  and 
die ;  if  attempts  are  made  at  conservation,  su])plementary  pathological 
changes  occur  which  result  in  the  death  and  decomposition  of  the 
organ.  Months  or  years  afterward  the  tooth  increases  in  opacity,  and 
if  the  pulp-chamber  be  opened,  the  pulp  is  seen  to  have  undergone 
decomposition. 

Treatment. — Pulpitis  when  fully  established  is  at  times  very  obdu- 
rate so  far  as  local  therapeusis  is  concerned.  The  same  local  measures 
apply  as  in  venous  hyperaemia,  local  bloodletting  when  feasible,  and 
applications  of  obtundents  and  sedatives.  Of  all  local  agents,  none 
appears  to  furnish  a  greater  measure  of  relief  than  applications  of  a  paste 
of  cocain  hydrochlorid  in  glycerin,  although  saturated  solutions  of  menthol 
and  thymol  are  both  effective.  Atropia  sulfate,  gi*.  j-3J,  is  also  markedly 
sedative.  These  applications  should  be  sealed  in  the  tooth  by  means 
of  temporary  stopping,  being  careful  that  no  pressure  is  made  upon  the 
pulp  or  it  will  respond  vigorously. 

Before  making  any  medicinal  applications  to  the  exposed  pulp  the 
cavity  should  be  freely  and  repeatedly  syringed  with  warm  antiseptic 
solutions,  a  50  per  cent,  solution  of  meditrina  answers  well.  Coagulant 
agents  are  not  used,  as  the  coagulum  formed  interferes  with  the  action 
of  other  remedies.  If  the  tooth  contain  a  large  filling,  it  is  removed, 
at  least  in  part,  until  access  to  or  proximity  to  the  pulp  is  attained. 

The  measures  stated  will  afford  partial  but  not  complete  relief;  gen- 
eral antiphlogistic  measures  are  indicated.  Of  these,  perhaps  the  most 
effective  is  local  bloodletting. 

Nancrede's  experiments  '  have  shown  that  one  of  the  most  effeetiv'e 
methods  of  unloading  an  area  of  engorgement,  is  to  take  a^vay  blood, 
and  establish  a  rapid  flow  through  veins  adjacent  to  the  area.  Making  a 
few  cuts  with  a  sharp  lancet  in  the  gum  overlying  the  root  of  the  affected 
tooth,  and  promoting  the  flow  of  blood  by  holding  warm  water  in  the 
mouth,  is  a  useful  measure. 

^  Warren's  Surgical  Pathology  and  Therapeutics. 
23 


354 


DESTRUCTIVE  DISEASES. 


Carefully  drying  the  gum  and  painting  over  a  small  area  canthar- 
idal  collodion  and  forming  a  blister  is  a  useful  means  of  derivation. 

The  continued  application  of  a  pepper  bag  to  the  gum,  and  painting 
the  gum  with  tincture  of  iodin,  both  tend  to  unload  the  engorged  pulp ; 
but  none  of  them  has  so  pronounced  effect  as  direct  local  bloodletting. 
If  the  patient's  repugnance  to  the  operation  can  be  overcome,  leeching 
is  an  effective  means  of  relief.  The  gum  is  scrubbed  clean,  the  leech 
being  very  loath  to  attach  itself  to  a  dirty  surface,  and  touched  with  a  solu- 
tion of  sugar.  The  (Swedish)  leech,  enclosed  in  a  small  test-tube,  is  to  be 
brought  to  work,  by  having  the  tube-mouth  pressed  upon  the  gum.  As 
soon  as  the  leech  is  engorged,  the  tube  is  withdrawn  slightly  and  salt 
(sodium  chlorid)  is  dropped  upon  the  animal,  which  then  falls  back  into 
the  test-tube. 

The  administration  at  night  of  ammonol,  grs.  x,  in  addition  to  local 
sedatives  and  local  bloodletting,  will  usually  secure  quiet.  If  the  pa- 
tient be  at  all  costive,  a  dose  of  Epsom  salt,  magnesium  sulfate,  a 
tablespoonful  in  a  goblet  of  water,  is  an  additional  means  of  relief. 
Quiet  of  the  pulp  must  be  secured  before  an  arsenical  application  is 
made,  or  the  latter  merely  increases  the  irritation  instead  of  promptly 
devitalizing. 


Fig.  278. 


Suppuration  of  the  Pulp. 

Definition. — By  suppuration  of  the  dental  pulp  is  meant  a  forma- 
tion of  pus  on  its  surface  (ulceration)  or  in 
its  substance  (abscesses).  It  occurs  both  as 
an  acute  and  as  a  chronic  affection. 

Causes. — The  immediate  cause  of  sup- 
puration of  the  pulp  is  the  ingress  of  pyo- 
genic organisms  to  the  pulp.  As  in  inflam- 
mation of  the  pulp,  while  usually  associated 
with  direct  exposure  of  the  pulp,  suppura- 
tion may  occur  in  pulps  covered  by  softened, 
or  even  unsoftened  dentin.^  "  Bacteria 
which  have  entered  the  body  through 
wounds  may  be  deposited  in  the  pulp  as 
well  as  in  any  other  part  of  the  body,  wher- 
ever there  may  be  a  locus  minoris  resistentice  at  the  time. 

Arkovy^  (Fig.  278)  first  observed  infection  of  the  pulp  while  still 
covered  by  a  layer  of  unsoftened  dentin.  Miller^  questions  whether 
bacteria  can  pass  through  any  but  very  thin  layers  of  dentin.  He 
states  *  that  sections  of  the  overlying  dentin  in  a  case  of  suppuration  of 

^  Miller,  Dental  Cosmos,  1894.  ^  Diagnostik  der  Zdhnkrankheiten. 

^  Micro-organisms  of  the  Human  Mouth.  *  Dental  Cosmos,  1 894. 


Invasion   of  pulp  by   micrococci. 

(Arkovy.) 


SUPPURATION  OF  THE  PULP. 


355 


the  pulp  showed  the  same  forms  of  bacteria  as  were  found  in  the  pulp 
itself. 

In  cases  where  suppuration  has  occurred  in  teeth  containing  large 
fillings  which  are  perfect  and  intact,  and  the  pulp  has  never  been 
exposed,  it  is  a  reasonable  inference  that  the  organisms  necessary  to 
pus-formation  have  found  their  way  to  the  dental  pulp  via  the  general 
circulation.  This  infection  in  purulent  pulpitis  is  a  mixed  one,  both 
cocci  and  bacilli  being  present,  and-  in  later  stages  of  degeneration 
other  forms  appear  also. 

Suppuration  of  the  pulp  is  a  not  infrequent  sequel  of  the  capping 
of  pulps  which  had  given  evidence  of  a  previous  hypememia  or  inflam- 
mation. 

Morbid  Anatomy  and  Patholog'y. — Anatomically  pulp  suppura- 
tion, purulent  or  pyogenic  pulpitis,  is  of  two  general  varieties ;  one 
begins  upon  or  close  to  the  surface  of  an  exposed  pulp,  and  graduallv 
destroys  the  organ  through  a  process  of  progressive  (Fig.  279)  ulcera- 

FiG.  279. 


A,  diagram  of  lower  molar,  with  caries  at  a  which  exposes  the  pulp  :  the  darkened  portion  at  6 
shows  the  extent  of  the  inflammation:  the  rest  of  the  organ  was  free  from  intiammatory 
change.  2?,  illustration  of  the  inflamed  tissue,  showing  a  part  destroyed  by  suppuration  at  a  ; 
the  odontoblasts  are  undermined  at  b;  the  bloodvessels  which  were  filled  with  blood-clot  in 
the  section  are  left  blank  here,  that  they  may  be  more  apparent.    (Black.) 


tion  ;  the  second,  that  confined  in  the  substance  of  the  pulp,  causes 
the  gradual  destruction  of  a  part  or  all  of  the  pulp  through  the  forma- 
tion of  circumscribed  abscesses  (Fig.  280). 


356 


DESTRUCTIVE  DISEASES. 


Fig.  280. 


Acute  suppurative  pulpitis  in  the  coronal  portion :  I,  intensely  inflamed  horn ;  A,  abscess ;  V,  blood- 
vessels engorged  with  blood ;  S,  superficially  inflamed  horn ;  N,  nest  of  inflammation.  X  10. 
(Bodecker.) 

Ulceration  of  the  Pulp. 

Of  these  two  forms,  ulceration  is  the  more  common.  The  capillaries 
(Fig.  279)  are  blocked  with  coagulated  blood  (they  are  left  open 
in  the  illustration  to  clearly  mark  their  position) ;  the  intercapil- 
lary  mesh  work  is  occupied  by  inflammatory  exudation  ;  the  surface  of 
the  pulp  is  eroded,  and  covered  with  pus-corpuscles ;  the  ulcerative 
process  is  undermining  the  layer  of  odontoblasts.  The  suppurative 
process  penetrates  the  body  of  the  pulp,  following  the  direction  of  its 
veins  and  hollowing  out  the  organ  into  a  deep  cavern.     Black  regards 


ABSCESS  OF  THE  PULP. 


357 


tlie  persistence  of  the  layer  of  odontoblasts  as  indicating:  an  inferior 
vitality,  as  it  shows  they  are  less  susceptible  of  change  of  form  than 
the  other  cells  of  the  organ. 

The  process  of  ulceration  may  continue  for  weeks  or  months  until 
the  entire  organ  has  been  destroyed  molecularly.  The  necrotic  por- 
tions undergo  putrefactive  decomposition,  probably  passing  through 
the  same  stages  that  any  albuminous  substance  passes  in  its  serial 
decomposition,  into  the  end-products — ammonia,  carbon  dioxid,  hydro- 
gen sulfid,  and  water. 

"  Very  interesting  and  instructive  results  were  obtained  by  examining 
material  from  diiferent  parts  of  the  same  tooth.  In  the  case  illustrated 
in  Fig.  281  the  pulp-chamber  at  a  was  wide  open  and  filled  Avith 
food-particles,  which  had  a  foul,  half-putrid  odor ;  at  b  the  pulp  was 
putrid  and  foul-smelling  ;  at  e  there  was  a  small  abscess,  filled  with 
pure  white  pus,  while  the  tissue  between  this  point  and  the  apex  of  the 
root  was  highly  inflamed  and  bright  red.  Material  from  the  pulp- 
chamber  {a,  Fig.  281)  contained  the  forms  shown  in  Fig.  282  ;  material 
from  point  6  those  shown  in  Fig.  283,  and  from  the  point  c  those  shown 
in  Fig.  284.  We  perceive  a  gradual  diminution  of  the  large  cocci,  and 
the  appearance  of  small,  delicate  cocci  and  diplococci "  (Miller).^ 


Fig.  281. 


Fig.  282. 


Fig.  283. 


Fig.  284. 


Fig.  285. 


--> 


Micro-orgauisms  found  in  cultures  from  a  gangrenous  pulp. 


Abscess  of  the  Pulp. 

Abscess  of  the  pulp  is  usually  situated  near  the  point  of  exposure 
of  the  organ.      It  may  be  confined  to  one  horn  of  the  pulp,  or  may 

1  Dental  Co.^mos,  1894. 


358 


DESTRUCTIVE  DISEASES. 


involve  nearly  the  entire  substance  of  the  pulp,  the  peripheral  tissue 
of  the  pulp  being  unbroken.  Abscess  may  exist  at  some  distance 
beneath  the  surface  of  the  pulp,  and  the  latter  be  still  covered  with 
a  layer  of  dentin.  The  writer  once  uncovered  the  horn  of  a  molar  pulp 
which  was  covered  by  a  lamina  of  hard  dentin,  and  no  fluid  appeared  ; 
but  upon  passing  a  sharp  probe  into  the  white  area  of  exposure  for  over 
one-eighth  of  an  inch  or  more  there  was  a  free  flow  of  pus  which  quickly 
filled  the  larger  carious  cavity.  A  pulp  removed  entire  from  a  tooth 
which  was  yellowish-white  in  color  and  unbroken  showed  upon  sec- 
tion its  interior  hollowed  out  into  an  enormous  abscess-cavity  (Fig. 
286).   The  bloodvessels  were  blocked ;  the  peripheral  tissues  were  unal- 

FiG.  286. 


Transverse  section  of  inferior  bicuspid  pulp,  one-half  diagrammatic:  a,  abscess-cavity;  &,  embry- 
onic cells  at  the  periphery  of  abscess-cavity ;  c,  occluded  bloodvessels. 

tered ;  between  the  odontoblasts  and  the  abscess-cavity,  the  latter  lined 
with  pus-corpuscles,  evidences  of  inflammation  were  plenty.  Black 
found  that  the  odontoblasts  retained  their  form  after  neighboring  cells 
of  the  pulp  had  been  destroyed. 

Miller's'  researches  show  a  preponderance  of  cocci  and  micrococci 
in  cases  of  enclosed  abscess  ;  cocci  and  diplococci  were  of  constant  occur- 
rence. Many  of  the  forms,  both  cocci  and  bacilli,  were  cultivable  upon 
gelatin  and  agar-agar.  Some  of  them,  cocci  and  bacilli,  brought  about 
the  liquefaction  of  gelatin  ;  others  did  not.  So  that  it  must  be  inferred 
that  infective  inflammation  and  necrosis  of  the  pulp  may  occur  without 
suppuration.  In  some  instances  streptococci  wore  found.  In  the  freely 
exposed  pulps  varieties  of  organisms  were  found  which  would  render 
clear  the  possibility  of  a  general  infection  by  way  of  the  dental  pulp. 

1  Dental  Cosmos,  1894. 


ABSCESS  OF  THE  PULP.  359 

Symptoms. — Many  cases  of  ulcerative  suppuration  of  the  pulp 
may  run  their  course  to  complete  or  almost  complete  destruction  of 
the  organ,  and  no  uneasiness  arise  until  septic  pericementitis  appears, 
which  it  almost  invariably  does  some  time  subsequent  to  death  of  the 
pulp.  In  other  cases,  however,  pains  characteristic  of  inflammation 
of  the  pulp  are  noted,  but  response  to  the  cold  test  has  almost  dis- 
appeared. Intense  pain  may  exist  when  the  pus  does  not  find  ready 
exit  owing  to  food-debris  being  massed  in  the  cavity  of  decay  or  to  the 
presence  of  a  large  filling.  The  condition  then  resembles  that  of  abscess 
of  the  pulp.  The  usual  history  of  the  latter  disease  is  as  follows  ;  in 
a  tooth  containing  an  enormous  filling,  one  in  which  the  pulp  has  been 
exposed,  or  in  a  tooth  having  a  large  carious  cavity,  the  patient  gives 
a  history  of  discomfort  or  decided  pain,  appearing  at  intervals ;  the 
existing  condition  having  been  ushered  in  by  dull,  gnawing  pain,  which 
is  usually  not  positively  located,  although  it  may  be.  The  pain  grows  in 
intensity,  and,  in  contradistinction  to  the  pulp-conditions  previously  de- 
scribed, pain  is  relieved  instead  of  increased  by  applications  of  cold.  It 
may  be,  however,  that  the  prolonged  contact  of  ice-water  may  induce 
a  response.  The  response  to  heat  is  marked,  so  that  a  mouthful  of  hot 
coffee  may  precipitate  an  attack  of  severe  and  continued  pain.  If  the 
pulp  be  freely  exposed  and  pricked  with  a  sharp  instrument,  a  flow 
of  pus  follows  in  many  cases,  and  the  relief  is  almost  immediate.  In 
the  earlier  stages  a  period  of  throbbing  pain  may  follow  evacuation  of 
the  pus. 

In  other  cases  the  response  to  heat  may  decrease  until  it  is  almost 
absent,  and  the  case  only  be  seen  Avhen  evidences  of  the  action  of  bac- 
terial products  upon  the  pericementum  appear,  which  they  usually  do 
in  the  later  stages  of  pulp  suppuration ;  when  the  tooth  becomes  loose, 
extruded,  and  tender  upon  percussion.  If  untreated,  symptoms  of  pulp 
and  pericemental  disturbance  may  disappear  for  weeks  or  months  ;  but 
if  the  parts  be  not  perfectly  sterilized  and  reinfection  prevented,  it  is 
only  a  question  of  time  when  septic  pericementitis  will  arise. 

Diagnosis. — The  most  valuable  diagnostic  sign  is  the  peculiar  reac- 
tion to  thermal  stimuli — the  decreasing,  then  absent  response  to  cold,  and 
the  increasing  reaction  to  applications  of  heat.  This  reaction,  together 
with  the  continued  gnaAving,  and  full  sensation  in  the  tooth,  usually 
affords,  a  diagnosis,  which  is  confirmed  by  evacuating  pus  from  the  pulp. 

Prognosis. — General  experience  regards  ulceration  and  abscess  of 
the  pulp  as  precursors  of  the  death  of  the  organ.  Usually  this  is  by 
progressive  suppuration.  It  is  undoubtedly  true,  however,  that  at- 
tempts at  circumvallation  of  the  dead  tissue  are  made  in  some  cases 
(Fig.  287).  The  pus-cells  undergo  degeneration  and  the  abscess-site 
may  be  the  seat  of  calcareous  deposits.     Even  in  these  cases  death  is 


360 


DESTRUCTIVE  DISEASES. 


delayed,  not  averted.     The  remainder  of  the  pulp  undergoes  atrophic 
changes,  and  commonly  suppuration  reappears. 

Treatment. — The  treatment  of  the  case  consists  in  relieving    the 
existing  pain,  completing  the  devitalization  of  the  pulp,  and  removing 


Fig.  287. 


Chronic  suppurative  pulpitis  terminating  in  calcification  of  the  pus  and  atrophy  of  the  pulps. 
Ai,  larger  abscess,  filled  with  calcified  pus ;  a^,  abscess  at  the  periphery  of  the  pulp ;  a^,  a",  small 
longitudinal  abscesses,  all  calcified ;  n,  calcified  nerve-bundle :  c,  c,  calcareous  depositions 
in  the  fibrous  pulp-tissue  ;  p,  p,  pigment-clusters  from  previous  hemorrhage.   X  10.    (Bodecker.) 

it  in  such  a  manner  that  no  organisms  or  dead  matter  are  carried  beyond 
the  apex  of  the  root. 

To  secure  relief,  evacuation  of  the  pus  is  imperatively  necessary. 
The  organ  is  freely  exposed,  exercising  no  pressure  in  gaining  free  access 
to  it.     If  pus  do  not  flow  upon  exposure  of  the  surface  of  the  pulp,  the 


ABSCESS  OF  THE  PULP.  361 

cavity  and  pulp,  the  tooth  being  under  rubber-dam,  are  drenched  with 
strong  antiseptics — a  spray  of  hydrogen  dioxid  or  of  meditrina — and  a 
sharp,  slender  sterilized  probe  is  quickly  passed  into  the  substance  of 
the  pulp,  when  if  pus  be  present  it  will  usually  escape  freely  through 
the  opening  thus  made. 

If  the  pus-formation  be  limited  and  circumscribed,  throbbing  pain 
raav  follow,  which  promptly  quiets  under  an  application  of  cocaiu  in 
glvcerin.  The  application  is  not  made  until  the  pus-flow  ceases.  A 
pellet  of  cotton  wet  with  a  3  per  cent,  solution  of  formalin,  or  a  satu- 
rated solution  of  thymol,  is  laid  upon  the  pulp  and  the  cavity  is  sealed 
for  tweuty-four  hours  (never  longer),  and  then  an  arsenical  application 
is  made.  Should  the  exposed  portion  of  the  pulp  be  insensitive  it  is 
burred  away  until  access  is  had  to  the  vital  portion,  where  the  arsenic  is 
to  be  applied.  Antiseptics  are  to  be  freely  used,  and  the  rubber-dam 
applied  before  entrance  to  the  pulp  for  any  therapeutic  applications. 


CHAPTER   XIX. 

CHRONIC  DEGENERATIONS  AND  DEVITALIZATION  OF   THE 

PULP. 

Some  of  the  chronic  degenerations  of  the  pulp  have  been  described 
under  the  head  of  secondary  deposits  in  the  pulp-substance.  The 
grades  of  hypersemia,  active  inflammation  and  suppuration  represent 
the  acute  degenerations  of  the  organ. 

Chronic  Inflammation. 

As  stated  in  Chapter  XVIII.,  ulceration  of  the  pulp  commonly 
pursues  a  chronic  and  progressive  course  until  the  organ  is  destroyed  ;  the 
condition  may,  therefore,  be  termed  chronic  purulent  pulpitis  (ulcerosa), 
as  an  inflammatory  zone  lies  beyond  the  line  of  suppuration.  This  con- 
dition has  already  been  discussed. 

Abscess  of  the  pulp  may  pursue  a  chronic  course,  as  stated.  Attempts 
are  occasionally  seen  at  repair  in  the  affected  pulp,  the  abscess-area 
being  marked  off",  and  the  elements  contained  in  it  becoming  the  seat 
of  calcareous  deposits. 

SCLEROSIS    OF    THE    PULP. 

Inflammation  of  a  low  grade  may  persist  in  the  pulp  for  long  periods^ 
giving  rise  to  an  increase  of  its  fibrous  tissue  with  atrophy  of  the 
pulp-elements,  producing  a  condition  similar  to  that  found  in  chronic 
interstitial  inflammation  in  some  other  tissues — a  sclerosis.  Instead  of 
the  usual  distribution  of  myxomatous  tissue,  bands  and  bundles  of 
fibrous  tissue  appear.  The  pulp  appears  shrunken  and  stiflF,  bloodvessels 
are  contracted,  and  the  nerve-fibres  have  undergone  partial  or  complete 
atrophy. 

Black  ^  found  that  in  the  late  stages  of  sclerotic  atrophy  areola© 
developed  in  the  bundles  of  connective  tissue,  the  inflammatory  elements 
having  disappeared,  and  the  areolse  being  occupied  by  fluid.  Arkovy 
describes  this  condition  as  reticular  atrophy  of  the  pulp  (Fig.  288). 
The  condition  would  point,  as  suggested  by  Black,  rather  to  venous 
hypersemia  as  the  cause  of  the  oedema  than  to  inflammation  ;  but  the 
evidences  of  former  chronic  inflammation  in  the  existence  of  the  bundles 
of  reticulated  tissue  show  this  to  have  been  the  essential  condition.    The 

^  American  System  of  Dentistry,  vol.  i. 
362 


CHRONIC  INFLAMMATION. 


363 


observations  of  the  same  writer  indicate  that  atrophy  of  the  odontoblasts 
is  a  usual  accompaniment  of  all  of  the  chronic  pulp  affections. 

Sclerotic  and  other  chronic  degenerations  of  the  jiulp  usually  pre- 
sent the  history  of  one  or  more  attacks  of  pulpitis  in  the  past,  with 


Fi«.  288. 


Chronic  inflamiuatiou  of  the  pulp,  areolatiou,  and  degeneration.    (Black.) 

more  or  less  continuous  uneasiness  extending  over  a  long  period.     The 
response  of  the  pulp  to  all  tests  becomes  diminished  and  dull. 
Treatment. — Such  pulps  are  to  be  devitalized  and  removed. 


Fig.  289. 


A,  a  first  lower  molar  with  a  cavity  at  a  completely  filled  by  a  hypertrophy  of  the  pulp,  which 
has  grown  out  through  the  orifice,  exposing  the  pulp  at  h.  B,  a  field  illustrating  the  tissue 
of  the  growth,  which  is  composed  almost  entirely  of  granulation-tissue  of  a  very  primitive 
type:  a,  a  covering  of  epithelium  presenting  papillae;  6,  epithelium  apparently  without 
papillae.    (Black.) 


364 


CHRONIC  DEGENERATIONS  OF  THE  PULP. 


CHRONIC    HYPERTROPHIC    PULPITIS. 

When  the  pulp  is  exposed  over  a  wide  area,  long-continued  chronic 
inflammation  may  lead  to  an  enlargement  of  the  organ  with  a  pro- 
trusion of  altered  pulp-mass  through  the  orifice  of  exposure,  producing 
the  condition  known  clinically  as  fungous  pulp.     When  the  growth 


Fig.  290. 


Hyperplastic  myxomatous  pulp,  which  filled  a  carious  cavity :  M,  lobules  made  up  of  papillee  of  a 
myxomatous  structure,  rich  in  capillary  and  venous  bloodvessels ;  G,  calcareous  globule : 
E,  epithelial  cover  of  papillae.  X  10.    (Bodecker.) 

extends  beyond  the  boundaries  of  the  orifice  and  then  increases  in  bulk 
it  forms  a  pedunculated  mass  to  which  the  term  polypus  of  the  pulp  has 
been  applied. 

Morbid.  Anatomy  and  Pathology. — The  growth  has  its  origin  in  a 
chronic  inflammation  of  the  body  of  the  pulp  ;  the  organ  swells,  and 
contact  with  the  sharp  edges  of  the  orifice  of  exposure  excites  a  con- 
tinued irritation  leading  to  further  proliferation  of  the  cells  of  the 
inflamed   part,  so  that  a  large   mass   of  embryonic   tissue  is   formed 


CHRONIC  HYPERTROPHIC  PULPITIS. 


365 


(Fig.  289),  termed  by  Black  grunulation-tissue  of  a  low  type.  As  in 
the  granulation-tissue  of  repair,  bloodvessels  grow  into  this  mass 
(Fig.  290),  so  that  it  may  bleed  at  a  slight  touch .  Black  noted  in  his 
case  illustrated,  a  covering  of  squamous  epithelium  upon  the  periph- 
ery of  the  growth,  which  might  be  interpreted  as  the  transformation 
of  mesoblastic  into  epiblastic  tissue,  but  the  correct  explanation  beyond 
doubt  is  that  advanced  by  the  same  author,  that  the  epithelium  is  trans- 
planted from  the  gums,  and  grows  after  the  manner  of  a  skin-graft. 

These  growths  may  undergo  further  changes  ;  higher  organization  of 
the  granulation-tissue  occurs  and  fibrous  tissue  is  formed  ;  the  cells  may 
undergo  degenerations,  first  granular,  then  fatty,  and  suppuration  and 


Fig.  291. 


mm 

Acute  pulpitis:  S,  secondary  dentin;  B,  bay-like  excavations  filled  with  medullary  or  inflam- 
matory corpuscles;  V,  transverse  section  of  a  bloodvessel;  M,  uniltiuuclear  body.  X  300. 
(Bodecker.) 

gangrene  may  occur.  Tomes  ^  records  a  case  where  calcification  of  a 
hypertrophied  section  of  a  pulp  occurred  ;  but  as  the  case  was  due  to 
traumatism  (fracture  of  a  tooth),  different  vital  conditions  existed  from 
those  in  the  cases  under  discussion.  Actual  calcification  of  the  mass 
is  scarcely  possible,  although  calcareous  degeneration  may  occur  (see 
Chapter  XVIII.). 

Resorption  of  the  walls  of  the  pulp-chamber  may  occur  as  an 
accompaniment  of  chronic  pulpitis.  What  appears  to  be  an  idiopathic 
dentin-resorption  is  described  in  Chapter  XVII.     Black  records  a  case 

^  Denial  Surgery,  3d  ed. 


366 


CHRONIC  DEGENERATIONS  OF  THE  PULP. 


Fig.  292. 


where  after  pulp-capping  in  a  lower  molar  and  the  insertion  of  a  large 
gold  filling  the  tooth  was  examined  at  the  end  of  ten  years ;  for  two  or 
three  years  the  pulp  had  given  evidences  of  irritability,  and  when  the 
pulp  was  removed  the  pulp-chamber  was  found  enormously  enlarged 
and  opening  into  the  pericementum  between  the  roots  of  the  teeth. 
Fig.  291  exhibits  resorption  of  previously  formed  secondary  dentin 
with  the  probable  agency  through  which  the  resorption  is  brought 
about.  The  area  of  resorption  is  invaded  by  numerous  multinucleated 
cells,  which  are  evidently  performing  the  function  of  odontoclasts. 

Symptoms. — The  symptoms  of  chronic  pulp  inflammations  and 
degenerations  are  usually  those  of  long-continued  discomfort,  with 
reflex  pains,  which  rarely  persist  into  the  latest  stages  of  degeneration. 
The  response  to  heat  and  cold,  present  at  first,  declines  until  the  pulp 
scarcely  reacts,  and  then  but  slowly. 

No  nerve-fibres  develop  in  the  hypertrophic  pulp-tissue,  so  that  the 
new  growth  has  no  sensitivity  in  itself,  although  pressure  upon  it  may 
cause  sharp  pain  through  the  still  vital  pulp-nerves  themselves. 

Diagnosis. — The  only  condition  with  which  hypertrophic  pulj)  may  be 
confounded  is  a  pedunculated  growth  of  gum-tissue  through  a  cavity  at  the 
neck  of  a  tooth  beneath  the  gum-margin.  It  is  important  to  differentiate  be- 
tween these  conditions,  because  if  an  appli- 
cation of  arsenical  paste  be  made  to  a  fun- 
gous gum,  the  destruction  of  tissue  may  ex- 
tend into  the  sound  pericementum.  The 
physical  appearances  of  the  two  are  alike  : 
they  both  bleed  freely  and  have  about  the 
same  degree  of  sensitivity.  If  the  de- 
generative changes  have  not  involved 
the  entire  substance  of  the  pulp,  a  reac- 
tion to  cold  may  be  secured,  which  will, 
of  course,  determine  the  diagnosis.  After 
isolating  the  tooth  under  rubber-dam  a 
spray  of  ethyl  chlorid  is  directed  against 
the  polypus,  and  when  it  is  entirely  insensitive,  a  sharp  blade  is  passed 
entirely  around  the  periphery  of  the  carious  cavity  detaching  the  fun- 
gous mass.  The  source  of  the  tumor  may  then  usually  be  clearly  seen. 
If  any  doubt  exist,  the  cavity  is  freely  syringed  with  antiseptics,  such 
as  pyrozone  or  meditrinia  ;  a  pellet  of  cotton  saturated  with  the  same 
is  inserted  and  over  it  temporary  stopping  is  firmly  packed.  If  the 
pulp  be  the  seat  of  the  growth,  it  may  rebel  against  the  pressure,  and 
require  a  less  firm  dressing,  so  that  slight  reaction  to  the  pressure  is  to 
be  regarded  as  evidence  that  the  growth  arises  from  the  gum. 
Treatment. — Devitalization  and  extirpation  of  the  pulp. 


A,  hypertrophy  of  gum  similating  fun- 
gous pulp,  B. 


DEVITALIZATION  OF  THE  DENTAL  PULP.  367 

DEVITALIZATION    AND    REMOVAL   OF    THE    DENTAL    PULP. 

It  will  have  been  noted  in  the  immediately  foregoing  chapters,  that 
the  intentional  devitalization  and  removal  of  the  dental  pnlp  are  de- 
manded as  an  indicated  therapentic  measure  in  pulp  diseases  which  tend 
to  self-destruction  of  that  organ.  The  one  universal  method  of  accom- 
plishing the  death  of  the  pulp  en  masse  is  by  applications  of  arsenic 
trioxid — arsenious  acid.  Although  other  means  have  been  suggested  and 
adopted,  none  is  so  certain  and  effective  as  this  one.  After  freely  expos- 
ing the  organ  to  be  destroyed,  a  general  anaesthetic  (nitrous  oxid)  has 
been  administered,  and  the  pulp  removed  while  the  patient  is  in  the 
anaesthetic  state.  Sprays  of  rapidly  vaporizable  substances,  such  as  ethyl 
or  methyl  chlorid,  directed  against  the  exposed  pulp,  the  tooth  being 
isolated  under  rubber-dam,  will  in  many  cases  render  the  pulp  entirely 
insensitive,  although,  as  a  rule,  they  fail  to  entirely  anaesthetize  to  the 
apical  foramen.  Applications  of  even  saturated  solutions  of  cocain 
being  ineffective,  it  has  been  suggested  to  inject  cocain  into  the 
pulp  :  the  surface  of  the  pulp  is  benumbed  by  applications  of  strong 
solutions  of  cocain,  the  needle  of  a  hypodermic  syringe  containing  a  solu- 
tion of  cocain  hydrochlorid  (from  4  per  cent,  to  10  per  cent.)  is  quickly 
thrust  into  the  pulp-canal,  and  a  drop  of  the  solution  forcibly  injected  ; 
in  a  few  seconds  the  pulp  may  be  so  benumbed  that  it  may  be  removed.^ 
This  procedure,  however,  appears  to  fail  as  often  as  it  succeeds. 

Cocain  cataphoresis  is  usually  effective,  although  in  conditions  of 
active  hypersemia  and  inflammation  even  the  maximum  current  and 
saturated  solutions  of  the  alkaloid  may  fail  to  subdue  the  irritability 
of  the  pulp.  The  pulp  may  be  destroyed  piecemeal  by  applications  of 
strong  caustics,  such  as  zinc  chlorid  or  chromic  acid  and  sodium  or 
potassium  hydrate,  but  their  action  is  slow  and  the  operation  tedious  ; 
moreover,  it  is  not  without  danger  ;  in  addition,  the  application  of  these 
agents  in  sufficient  strength  is  usually  followed  by  severe  paroxysms  of 
pain. 

Arsenious  acid — arsenic  trioxid — is  prompt,  certain,  and  complete  in 
its  action  and  has  maintained  its  position  in  dental  therapeutics  since 
introduced  by  Spooner  for  this  purpose  in  1836.  The  progenitor  of  all 
present  arsenical  pastes  was  the  formula  of  J.  D.  White,  given  some 
forty  years  ago  : 

It.  Arsenious  acid     1 

TIT  1   .  1     1  >  "" 

Morphise  sulph.,  J 

Carbolic  acid,  q.  s.  ft.  paste. — M. 

>  Maxfield,  Proc.  New  Jersey  State  Dented  Society,  1894. 


368  CHRONIC  DEGENERATIONS  OF  THE  PULP. 

This  was  followed  twenty -five  years  ago  by  that  of  J.  Foster  Flagg : 

^.  Arsenious  acid,  gr.  x  ; 

Morphiee  acetat.,  gr.  xx  ; 

Ol.  carophyllum,         q.  s.  ft.  paste. — M. 

The  advantages  of  the  latter  were  demonstrated  clinically,  and  within 
a  few  years  scientifically.  The  purpose  and  effects  of  the  ingredients 
of  arsenical  pastes  will  become  more  evident  after  an  examination  of 
the  effects  of  arsenic  upon  the  pulp. 

Effects  of  Arsenic  on  the  Pulp. — Since  the  introduction  of  arsen- 
ical preparations  definite  physiological  effects  have  been  noted  following 
their  use.  First,  a  grumbling  pain,  rising  in  a  few  hours  to  acute  par- 
oxysmal pain  ;  then  a  gradual  and  in  some  cases  a  sudden  cessation  of 
pain,  after  which  the  pulp  fails  to  respond  to  applications  of  cold. 

These  effects  were  explained^  as  follows  :  "A  minute  portion  of  the 
arsenic  being  introduced  into  the  pulp-circulation,  acts  as  a  dynamic, 
vital  irritant,  causing  determination  of  blood  to  the  part "  {i.  e.,  arterial 
hyperaeraia),  and  gives  rise  to  the  throbbing  pain.  Congestion  (presum- 
ably venous  hypersemia)  follows,  occasioning  the  cessation  of  throbbing 
and  the  appearance  of  dull,  gnawing  pain  in  the  tooth.  "  The  death  of 
the  pulp  en  masse  is  due  to  strangulation  of  the  vessels  at  the  apex  of 
the  root  in  consequence  of  the  congestion." 

The  subsequent  decomposition  of  the  pulp — putrefaction — was 
deemed  due  to  the  amount  of  arsenic  absorbed  by  the  pulp  prior  to  its 
death  being  insufficient  to  preserve  it.  Flagg  states  ^  that  tests  of  pulp 
which  have  been  devitalized  by  arsenic  show  but  an  infinitesimal 
amount  of  the  agent  to  be  present  in  them. 

The  same  writer  points  out  the  existence  of  pericemental  irritation 
in  the  last  stages  of  pulp-devitalization  ;  that  is,  in  from  four  days  to  a 
week  after  the  application ;  regarding  it  as  not  due  to  the  irritation  pro- 
duced by  the  arsenic,  but  to  an  extension  of  the  vascular  condition  from 
the  pulp ;  the  pericemental  disturbance  is  limited,  ceasing  in  a  few 
hours  or  a  day  or  two. 

Arkovy  ^  was  the  first  to  point  out  the  details  of  the  action  of  arsenic 
upon  the  dental  tissues  : 

"  1.  AS2O3  brought  into  contact  with  the  tooth-pulp  acts  in  the  follow- 
ing way  :  a  certain  degree  of  inflammatory  hypersemia,  total  or  partial, 
depending  upon  the  quantity  of  the  agent  applied,  sets  in ;  the  blood- 
vessels become  expanded,  and  here  have  a  tendency  to  thrombosis. 
This  latter  effect  may  also  be  in  connection  with  embolism  of  the  capil- 
laries, when  the  agent  is  quickly  taken  up  into  the  bloodvessels. 

1  J.  Foster  Flagg,  Denial  Cosmos,  1877.  ^  Ibid. 

^  Transactions  Internal.  Med.  Cong.,  London,  1881. 


DEVITALIZATION  OF  THE  DENTAL  PULP.  369 

"  2.  AS2O3  produces  no  coagulatiun  of  tissue  whatever. 

"  3.  It  has  a  specific  influence  upon  the  blood-corpuscles,  combining 
with  the  haemoglobin  to  form  a  compound  of  arsen-luemoglobin,  and  of 
this  chemical  process  there  seems  to  be  evidence  in  the  profuse  yelloAV- 
ish  tinge  of  the  whole  pulp-tissue  and  in  the  discoloration  of  blood  in 
several  of  the  bloodvessels. 

"  4.  In  nearly  every  case  it  is  taken  np  in  substantia  (in  form  of 
molecules)  into  the  blood-ways ;  when  there  it  produces,  besides  the 
above-mentioned  changes,  granular  detritus  of  the  contents  and  anaemic 
collapse — shrinkage,  the  latter  effect  being  brought  about  nearly  exclu- 
sively in  cases  where  greater  doses  were  used. 

"  5.  The  bulk  of  the  pulp-tissue — viz.,  connective-tissue  fibres  and 
odontoblasts — undergoes  no  change  whatever  ;  not  so  the  connective- 
tissue  cells,  which  increase  three  or  four  times  their  normal  size. 

''  6.  The  special  action  of  arsenic  trioxid  npon  the  nerve-elements 
consists  in  the  following  :  the  neurilemma  is  only  so  far  influenced  that 
its  nuclei  are  somewhat  increased  ;  a  more  essential  change  takes  place 
in  the  axial  part,  where,  after  the  application  of  more  than  one  mgrm. 
granular  destruction  of  myelin  sets  in,  and  the  axis-cylinder  commences 
here  and  there  to  disappear.  A  very  surprising  alteration  may  be  seen  in 
the  notchy  tumefaction  of  the  axis-cylinder,  described  heretofore  almost 
only  in  cases  of  central  lesions. 

"  7.  All  these  alterations  occur  in  and  among  normal-looking  tissue. 

"  8.  The  action  of  arsenic  trioxid  is  macroscopically  exhibited  by  a 
brownish-red  tingeing  of  the  whole  or  of  certain  parts  of  the  pulp- 
body,  as  well  as  of  the  neighboring  dentin  and  the  cementum,  this  latter 
in  cases  treated  with  greater  doses — viz.,  two  to  five  mgrms.  This 
alteration  is  most  expressed  at  the  top  of  the  crown-pulp  and  at  the 
apical  one-fourth  to  one-third  part.  This  circumstance  may  be  con- 
sidered as  an  external  evidence  of  the  devitalization  being  completely 
attained  to." 

In  some  cases  the  pinkish  discoloration  of  the  dentin  may  be  marked  ; 
the  broken-do\^'n  corpuscles  of  the  extravasated  blood  have  their  color- 
ing-matter taken  up  by  the  odontoblasts,  and  being  distributed  through 
their  protoplasmic  processes  produce  a  condition  technically  known  as 
suffiision.  The  same  result  may  be  an  attendant  upon  injury  to  the  ves- 
sels from  other  causes,  from  sudden  thrombosis,  as  when  teeth  are  moved 
too  rapidly  in  regulating. 

Miller's  experiments^  upon  the  tails  of  mice,  made  without  and  with 
rings  at  the  root  of  the  tail  to  simulate  the  surroundings  of  the  apical 
vessels  of  a  tooth  ;  made  without  and  with  encasement  of  the  tails  in 
plaster-of-Paris  to  imitate  the  rigid  surroundings  of  the  dental  pulp  : 

1  Denial  Cosmo.%  1894. 
24 


370  CHRONIC  DEGENERATIONS  OF  THE  PULP. 

showed  that  in  the  absence  of  the  plaster  encasement,  enormous  oedema 
of  the  tail  was  produced  and  a  sensory  paralysis  of  the  hind  limbs ; 
complete  anaesthesia  of  the  tail  occurred  in  forty-eight  hours.  "  The 
action  of  arsenic  appeared  somewhat  accelerated  when  a  glass  ring 
"was  applied  close  to  the  root  of  the  tail.  In  more  than  forty  cases 
there  was  not  one  in  which  the  action  of  the  arsenic  extended  beyond 
the  ring,  and  the  action  was  not  appreciably  affected  by  enclosing  the 
tails  in  plaster  casts.  The  action  of  the  arsenic  is  of  a  progressive 
nature,  beginning  at  the  point  of  application  and  extending  gradually 
in  each  direction."  The  indication  is,  therefore,  that  a  minute  portion 
of  the  arsenic  is  taken  into  the  pulp ;  this  may  be  either  through  the 
odontoblastic  processes  in  cases  of  non-exposed  pulps,  or,  when  exposed, 
by  the  cells  themselves,  and  causes  violent  reaction  of  the  vessel-walls, 
which  dilate  to  their  utmost ;  extravasation  of  corpuscles  occurs  and 
circulation  is  checked  at  the  end  of  the  root,  the  pulp-vessels  are  me- 
chanically occluded,  so  that  no  absorbed  arsenic  is  carried  beyond  the 
pulp  extremity.  The  arsenic  exercises  its  paralyzant  and  degenerative 
influence  upon  the  nerves  of  the  pulp,  after  first  inducing  a  violent  irri- 
tation, which  may  be  due  to  the  specific  action  of  the  arsenic  upon  the 
nerves  or  to  the  intense  hyperaemia.  The  strangulation  theory  can- 
not, however,  hold  in  all  cases,  for  progressiv^e  death  of  structures 
free  to  expand  occurs  after  applications  of  arsenic,  so  that  the  specific 
and  gradual  action  of  the  poison  must  be  the  important  factor.  Strang- 
ulation would  imply  an  always  sudden  death  of  the  pulp  en  masse, 
which  evidently  does  not  always  occur,  for  complete  death  of  the  organ 
may  be  gradual  and  require  several  days.  In  other  cases  repeated 
applications  may  be  necessary. 

These  experiments  illustrate  the  danger  of  making  arsenical  appli- 
cations to  immature  teeth  or  those  in  which  resorption  of  the  roots  is  in 
progress.  If  the  full  constriction  of  the  apical  foramen  has  not 
occurred,  it  is  possible  that  a  portion  of  the  arsenic  may  be  carried 
beyond  the  apex  of  the  root  into  the  pericementum.  This  danger,  it 
may  be  remarked,  has  been  recognized  for  the  past  thirty  years. 

Variations  in  the  Action  of  Arsenic. — In  most  cases  of  fully 
formed  teeth  in  young  adults,  an  application  of  arsenical  paste  directly  to 
the  exposed  pulp  will  be  followed  by  the  complete  death  of  the  organ 
in  forty-eight  hours.  At  the  expiration  of  that  time  a  sterilized  broach 
may  be  passed  almost  to  the  apex  of  the  root  and  the  pulp  removed 
en  masse  without  pain.  If  pulp-nodules  exist,  the  action  of  the  arsenic 
may  be  delayed  or  in  some  cases  be  almost  nil.  In  calcareous  and  oth^r 
chronic  pulp-degenerations  the  action  is  also  delayed.  If  arsenical  appli- 
cations are  made  over  a  layer  of  dentin,  the  same  delay  is  noted,  and  is 
increased  in  very  mature  teeth. 


DEVITALIZATION  OF  THE  DENTAL  PULP.  371 

Some  pulp,  irre.s})ective  of  the  pulp  condition,  exhibits  a  peculiar 
idiosyncrasy  in  resisting  the  action  of  arsenic,  requiring  large  doses  and 
a  week  or  longer  application  before  succumbing. 

Form  in  which  Used. — Miller^  has  pointed  out  the  influence 
exerted  by  the  several  agents  used  in  conjunction  with  the  arsenic.  The 
constituents  of  the  common  prescription, 

11.  Acidi  arsenosi,  1 

HI-       1  •  .        r  ««• 

Morphue  acetatis,    J 

Acid,  carbolici,  q.  s.  ft.  paste. — M., 

were  supposed  to  have  the  following  properties  :  the  arsenic  trioxid 
being  the  devitalizing  agent ;  the  morphia  is  used  to  lessen  or  deaden 
the  pain  of  the  application  ;  the  carbolic  acid  is  an  analgesic  men- 
struum. Carbolic  acid  and  other  coagulants  produce  an  eschar,  a 
coagulum,  which  delays  the  absorption  of  the  arsenic,  so  it  should 
be  discarded.  It  has  always  been  questioned  just  what  extent  of 
analgesic  effect  morphia  possessed  ;  some  say  none,  holding  that  the 
lessened  pain  is  due  to  the  reduction  of  the  amount  of  arsenic  applied. 
Certainly,  the  painful  effects  of  the  poison  do  appear  to  be  modified  by 
the  size  of  the  dose  employed.  Iodoform,  also  used  as  an  analgesic 
ingredient  in  some  prescriptions,  is  of  doubtful  value.  Cocain,  natu- 
rally, was  made  one  of  the  ingredients  of  arsenical  pastes  soon  after 
its  introduction  into  the  materia  medica.  The  usual  prescription  at 
present  is  : 

I^.  Acidi  arsenosi,  gr.  x  ; 

Cocain.  hydrochlorid.,  gr.  xx  ; 

Ol.  cinnamomi,  q.  s.  ft.  paste. — M. 

Miller  suggests  using  thymol  in  connection  with  arsenic,  it  being 
both  analgesic  and  antiseptic.  He  oifers  the  following  general  rules  as 
deductions  from  his  observations  : 

1.  The  rapidity  and  intensity  of  the  action  of  arsenious  acid  depend, 
under  certain  circumstances,  to  a  very  considerable  degree  upon  the 
substance  or  substances  with  which  it  is  incorporated. 

2.  Where  there  is  but  a  small  point  of  exposure,  and  in  particular 
where  extensive  calcification  has  taken  place  in  the  pulp,  escharotics 
should  be  avoided,  since  the  coagulation  of  the  tissue  retards  the  absorp- 
tion of  the  arsenic.  This  retardation  is  but  slight  where  there  is  a 
broad  surface  of  exposure.  In  stubborn  cases,  where  applications  of 
the  ordinary  paste  fail  to  efPect  the  devitalization,  a  paste  consisting  of 
arsenious  acid  in  oil  of  cloves,  glycerin,  or  salt  solution  should  be 
employed,  undiluted  by  any  third  constituent. 

1  Dental  Cosmos,  189-4. 


372  CHRONIC  DEGENERATIONS  OF  THE  PULP. 

3.  Thymol  is  worthy  of  a  trial  as  a  substitute  for  morphia,  on 
account  of  its  anaesthetic  and  antiseptic  properties. 

4.  For  devitalizing  pulps  of  temporary  teeth  or  remains  of  pulp- 
tissue  in  root-canals,  arsenious  acid,  if  employed  at  all,  should  be 
diluted  with  two  or  three  parts  of  some  other  constituent  (thymol,  zinc 
oxid,  morphia,  iodoform). 

Cobalt  was  introduced  by  Robert  Arthur  as  a  devitalizing  agent  some 
forty  years  ago.  Within  recent  years  it  has  been  employed,  notably 
by  the  Herbst  method  (which  see),  to  destroy  pulps.  The  cobalt  paste 
of  Herbst  was  analyzed  by  E.  C.  Kirk  '  and  found  to  consist  of  metallic 
arsenic  and  cocain  hydrochlorid.  Kirk  suggests  that  free  acids  which 
cocain  salts  may  contain,  or  the  chlorin  from  the  chlorid,  may  combine 
with  the  metallic  arsenic  and  form  soluble  salts.  Commercial  cobalt 
will  certainly  devitalize  the  dental  pulp,  but  it  is  in  consequence  of  the 
arsenic  contained  in  it. 

Mode  of  Application. — It  is  always  to  be  borne  in  mind  that  arsenic 
acts  upon  all  living  tissue  in  the  destructive  manner  that  it  does  upon 
the  dental  pulp,  so  that  the  first  consideration  in  making  an  arsenical 
application  is  the  precise  placing  and  sealing  of  the  paste  so  that  none 
of  it  shall  come  in  contact  with  any  vital  tissue  other  than  the  pulp. 
Second,  in  conditions  of  venous  hyperemia  or  inflammation  arsenic, 
instead  of  exercising  its  actively  destructive  property,  serves  but  to 
exaggerate  the  existing  vascular  conditions  with  the  attendant  symp- 
tom, pain.  Third,  but  a  minute  quantity  of  arsenic  is  required  to  kill 
a  pulp ;  and  if  an  excess  be  used,  the  attendant  pain  is  much  increased. 
Fourth,  if  any  pressure  be  exerted  upon  the  pulp  by  the  material  used 
to  seal  in  the  paste,  the  pain  will  be  increased  in  the  degree  of  the 
pressure.  Fifth,  in  the  vast  majority  of  cases  the  pulp-cavity  is  the 
seat  of  infection,  so  that  careful  sterilization  should  precede  the  appli- 
cation of  arsenic.  Sixth,  to  insure  accuracy  of  placement,  freedom  from 
leakage,  and  sterilization,  the  application  of  the  rubber-dam  should  pre- 
cede the  placing  of  the  arsenical  paste. 

In  the  vast  majority  of  cases  arsenical  applications  are  made  directly 
to  the  point  of  exposure  in  the  cavity  of  decay.  In  case  the  gum  over- 
hang the  cavity-margins,  it  must  be  removed  until  the  margins  are  clear 
and  visible.  The  cavity  is  syringed  repeatedly  with  warm  })yrozone ; 
and  a  pledget  of  cotton  saturated  with  meditrina,  thymol  (saturated  solu- 
tion), or  hydronaphthol  (alcoholic  solution),  and  over  this  a  pellet  of  cot- 
ton which  has  been  dipped  in  sandarac  varnish  is  placed.  The  dressing 
must  be  renewed  in  twenty-four  hours.  Coagulating  antiseptics  should 
not  be  used,  as  they  form  a  coagulum  upon  the  surface  of  the  pulp  and 
interfere  with  the  action  of  the  arsenic.  If  the  cavity  be  upon  the  buccal 
1  Dental  Cosmos,  1893,  p.  247. 


DEVITALIZATION  OF  THE  DENTAL  PULP.  373 

face  of  a  molar,  or  in  a  situation  where  the  gum-tissue  has  hypertrophied 
and  covers  tlie  cervit-al  portion  of  the  cavity  as  a  bulbous  mass,  the  re- 
dundant portion  may  be  trimmed  away  by  means  of  a  sharp,  curved 
bistoury  or  gum-laneet. 

As  soon  as  the  cervical  border  of  the  cavity  is  clear  of  the  overhang- 
ing gum  it  is  syringed  with  warm  antiseptics  and  the  rubber  dam  ad- 
justed. The  softened  dentin  is  freely  cut  away  until  the  cavity  has  a 
retentive  form  and  the  area  of  exposure  is  clearly  outlined.  If  the 
pulp  be  the  seat  of  immediate  or  very  recent  hyperaemia  or  inflamma- 
tion, anodyne  antiseptics  should  be  sealed  in  the  cavity  for  a  day  or  two 
before  making  the  arsenical  application.  An  admirable  prescription  in 
this  connection  is  thymol  or  menthol  with  cocain  made  into  a  paste  with 
glycerin  ;  a  pledget  of  cotton  dipped  in  this  mixture  and  laid  upon  the 
exposure  is  sealed  in  the  cavity  by  means  of  softened  temporary  stop- 
ping applied  without  pressure. 

If  the  cavity  be  inaccessible,  where  the  rubber-dam  cannot  be  used 
to  exclude  fluids,  and  where  an  arsenical  application  cannot  be  made 
with  precision  and  without  fear  of  dislodging  it  while  it  is  being  sealed 
in,  it  is  advisable  to  form  a  special  cavity  for  its  reception.  This  should 
always  be  made  when  possible  in  a  line  of  direct  approach  to  the  pulp- 
canals.  The  cavity  is  to  be  made  as  deep  as  possible  without  plunging 
into  the  pulp.  As  a  rule,  in  the  conditions  demanding  extirpation  of 
the  pulp  the  dentin  is  insensitive  or  nearly  so,  so  that  the  pulp  may 
be  almost  exposed  without  pain.  An  exception  to  this,  however,  is 
found  when  pulp-nodules  exist,  when  the  dentin  may  be  exquisitely 
sensitive.  In  these  cases  two  or  more  applications  of  the  paste  are 
required  ;  as  soon  as  the  pulp  can  be  exposed,  a  direct  application  of  the 
paste  is  to  be  made. 

To  make  the  application,  the  cavity  is  sterilized,  placed  under 
rubber-dam,  and  an  application  of  pyrozone  is  made,  remaining  five 
minutes  or  longer  ;  the  cavity  is  dried,  and  a  piece  of  cotton,  not  larger 
than  a  pin-head,  is  to  have  a  minute  portion  of  the  paste  placed  upon  it, 
and  then  laid  gently  upon  the  spot  of  exposure.  It  is  the  general 
practice  to  seal  in  the  arsenic  with  cotton  and  sandarac,  or  temporary 
stopping.  The  first  becomes  very  foul  in  twenty-four  or  forty-eight 
hours,  and  swells,  causing  pressure  upon  the  pulp  and  much  pain. 
Temporary  stopping,  made  very  soft,  may  be  manipulated  so  that  it 
causes  no  pressure,  but  some  slight  pressure  is  the  rule  ;  so  that  a  thin 
paste  of  zinc  phosphate  is  to  be  recommended  as  the  sealing-material, 
"  Flowed  over  the  arsenical  application  and  removing  the  rubber-dam 
before  the  cement  has  hardened  will  diminish  or  prevent  the  pain  inci- 
dent to  the  application  and  render  the  cement  easy  of  removal." ' 

•  Miller. 


374  CHRONIC  DEOENEBATIONS  OF  THE  PULP. 

Instead  of  placing  the  paste  upon  a  pledget  of  cotton,  cotton-fibre 
may  be  rolled  in  an  arsenical  paste,  dried,  and  preserved ;  in  this  con- 
dition it  is  known  as  devitalizing  fibre.  The  advantage  of  this  fibre  is 
that  a  dry  arsenical  application  may  be  made  to  the  pulp,  so  that  there 
will  be  no  danger  of  oozing.  The  length  of  time  required  for  devitaliza- 
tion is  usually  about  twenty-four  hours,  although  in  a  large  number 
of  cases  sensitivity  will  still  exist  at  the  upper  third  of  the  canal  por- 
tion of  the  pulp  at  the  end  of  two  days.  At  the  end  of  four  or  five 
days  the  pulp  will  in  most  cases  have  completely  sloughed  at  the  apex. 
To  relieve  unusual  pain  following  an  arsenical  application  general 
anodynes  or  sedatives  will  at  times  be  required.  While  morphia 
sulfate,  gr.  \,  will  deaden  the  pain,  the  after-effects  of  morphia  are 
uncomfortable.  The  coal-tar  derivatives  are  useful ;  gr.  x  of  ammonol, 
or  phenacetin  and  exalgin,  da.  gr.  iij,  administered  at  the  time  of  the 
application  and  repeated  upon  retiring,  will  act  effectively. 

An  annoying  type  of  case  is  where  approach  is  to  be  made  in  an 
approximal  cavity  with  a  cervical  margin  beyond  the  gum-margin, 
where  access  to  the  pulp-canals  Avill  be  direct  after  devitalization,  and 
yet  the  cavity  cannot  be  kept  dry.  Such  cases  are  managed  after  the 
following  manner  :  a  small  piece  of  temporary  stopping  is  softened  and 
pressed  against  the  cervical  wall  of  the  cavity,  but  not  covering  the 
pulp-exposure;  the  stopping  is  then  moulded  against  the  gum  press- 
ing it  back  (Fig.  293)  :  this  guard  accurately 
placed  will  protect  the  gum  against  arsenical 

J^(  I  poison  by  preventing  oozing  of  the  latter  from 

T.L  ii  ''^^^    \  about  the  cervical  edge.     An  application  of  de- 

\^  v¥^    '  r    ^^V\         vitalizing  fibre  is  then  made,  and  sealed  as  usual. 
'•'1\       \\'''-\   '^~'^v\  Cervical   cavities    not    having   a   retentive 

v\  V  \v"'; '-^^S:^)/^^       form,  and  abraded  teeth,  offer  difficulties,  which 
•'^,^|:/.V'--'- ''•''•■  are  overcome  by  drilling  a  special  pit  for  the 

reception  of  the  paste. 
In  cases  where  there  are  pulp-nodules,  and  where  chronic  degen- 
erations of  the  pulp  exist,  the  arsenic  is  removed  at  the  end  of  the 
usual  devitalizing  period  and  free  entrance  is  made  to  the  pulp,  cutting 
away  all  insensitive  portions  ;  if  pulp-nodules  can  be  lifted  away  pain- 
lessly, they  are  removed,  and  a  fresh  application  of  arsenic  is  made, 
to  remain  again  several  days.  In  all  of  these  cases,  to  effectually  devi- 
talize it  may  be  necessarv  to  apply  a  paste  of  arsenic  trioxid  in  glycerin, 
or  in  one  of  the  essential  oils.^ 

Removal  of  Pulp. — At  the  end  of  four  or  five  days  the  dressing 
seal,  and  cotton  containing  the  paste  are  removed,  the  cavity  freely 
syringed  with  hydrogen  dioxid,  and  the  rubber-dam  applied.     Large 

1  Miller. 


Fig.  293. 


DEVITALIZATION  OF  THE  DENTAL  PULP.  375 

sterilized  rose  burs  are  u.sed  to  open  the  pulp-chamber  freely  and  to 
remove  al/  softened  dentin  (all  softened  dentin  being  always  removed 
from  pulpless  teeth). 

The  cavity  is  now  to  be  given  such  form  that  pulp-broaches  may  be 
passed  directly  and  freely  to  the  apex  of  each  root.  This  rule  is  to  be 
followed,  no  matter  how  much  tooth-substance  is  sacrificed  to  carry  it 
into  eifect.  As  the  future  health  of  the  tooth  depends  almost  entirely 
upon  the  thoroughness  with  wliich  each  canal  is  cleansed,  sterilized,  and 
hermetically  sealed  at  the  apex,  it  is  evident  that  the  removal  of  crown- 
tissue  is  a  small  evil  compared  with  incomplete  entrance  to  and 
cleansing  of  a  canal. 

A  new  and  perfect  pulp-broach  is  dipped  in  carbolic  acid  and  gently 
passed  to  the  apex  of  the  root ;  the  teeth  of  the  broach  are  turned  away 
from  the  pulp  until  the  instrument  is  fully  inserted,  when  the  broach 
is  turned  so  that  its  teeth  shall  engage  the  entire  length  of  the  pulp, 
which  may  then  usually  be  removed  entire.  In  multirooted  teeth,  after 
removing  the  body  of  the  pulp,  the  largest  canal  is  first  entered  and 
the  pulp  removed ;  this  canal  is  then  to  be  loosely  filled  with  a  twist 
of  cotton  containing  an  antiseptic  ;  carbolic  acid,  formalin  in  2  per  cent, 
solution,  or  hydronaphthol.  The  next  largest  canal  is  cleansed  and 
treated  in  the  same  manner,  and  after  this  the  smallest  canal. 

Removal  of  the  pulp  entire  may  nearly  always  be  assured  if,  after 
an  arsenical  application  have  been  in  the  tooth  for  three  or  four  days, 
it  be  removed,  and  a  dressing  of  formalin,  5  per  cent.,  be  inserted  for 
several  days.     The  pulp  is  rendered  tougher  by  this  agent. 

In  canals  too  small  to  admit  the  pulp-broaches,  cleansing  and  uniform 
enlarging  of  the  canals  are  accomplished  by  means  of  chemical  agents. 
The  general  cavity-wall  is  varnished  to  prevent  the  action  of  the 
acid  upon  the  dentin,  and  by  means  of  a  pair  of  Flagg's  dressing- 
pliers  or  a  minim-dropper  a  drop  of  sulfuric  acid  (50  per  cent,  solu- 
tion) is  deposited  at  the  mouth  of  the  canal  to  be  operated  upon.  The 
finest  size  of  Donaldson's  canal-cleanser  is  then  passed  into  the  canal 
as  far  as  it  will  go,  using  a  pumping  movement  to  carry  the  acid  further 
into  the  canal  and  to'  scrape  the  canal-walls  softened  by  the  action  of 
the  acid.^  The  acid  chemically  destroys  any  organic  matter — /.  e.,  pulp- 
tissue — present,  releases  the  calcium  of  the  dentin  from  its  combination, 
and  forms  calcium  sulfate,  which  is  mechanically  removed  by  scrapers. 
The  operation  is  continued  until  the  apex  of  the  root  is  reached. 

If  all  of  the  operations  have  been  carried  out  with  antiseptic  pre- 
cautions, sterilizing  the  cavity,  placing  it  under  rubber-dam,  drenching 
the  pulp  with  antiseptics,  and  using  none  but  sterilized  instruments,  the 
canals  are  now  in  an  aseptic  condition  and  are  to  be  hermetically 
'  Callahan,  Proc.  Ohio  State  Dental  Society,  1894. 


376  CHRONIC  DEGENERATIONS  OF  THE  PULP. 

sealed — filled.  If  the  pulp  have  been  removed  within  two  days  from 
the  application  of  the  arsenic,  bleeding  may  follow  the  extirpation 
of  the  pulp,  or  a  mild  and  what  should  always  be  a  transient  peri- 
cementitis may  arise.  In  case  of  bleeding,  applications  of  hydrogen 
dioxid  will  act  as  a  styptic  and  also  decompose  and  remove  the  blood. 
The  canal  should  not  be  sealed  until  the  bleeding  ceases.  The  transient 
pericementitis  is  most  common  in  cases  where  slight  sensitivity  of  the 
apical  portion  of  the  pulp  existed  at  the  time  of  extirpation,  and  is 
evidenced  by  soreness  of  the  tooth,  tenderness  upon  percussion.  This 
irritation  may  be  pronounced  if  immediate  root-filling,  the  usual  pro- 
cedure in  cases  of  intentional  devitalization  and  removal  of  the  pulp, 
be  practised.  If  tenderness  appear  during  or  immediately  after  extir- 
pation, it  promptly  subsides  upon  filling  the  pulp-canals  with  a  saturated 
solution  of  menthol  in  chloroform,  filling  the  canals  loosely  with  cotton, 
hermetically  sealing  the  cavity,  and  painting  the  gum  overlying  the 
tooth  with  tr.  iodin.  The  canals  should  remain  unfilled  for  a  week, 
until  all  evidences  of  pericemental  irritation  subside.  Before  filling, 
the  canals  should  be  thoroughly  washed  with  hydrogen  dioxid. 

The  Root  Canal-filling. — The  features  to  be  [)ossessed  by  a  canal- 
filling  should  be:  first,  it  should  be  non-irritating;  secondly,  it  shall 
hermetically  seal  the  canal ;  thirdly,  it  shall  be  unalterable  in  the  condi- 
tions surrounding  it.  If  possible,  it  should  be  continuously  antiseptic, 
and  be  removable  if  subsequent  conditions  ever  demand  its  removal. 
The  materials  most  employed  are  zinc  oxychlorid,  and  gutta-percha, 
solid  and  in  solution,  or  combinations  of  both.^ 

The  present  tendency  is  to  substitute  melted  paraffin,  containing 
antiseptics,  for  other  materials.  The  choice  is  clearly  indicated  as  a 
rational  therapeutic  measure.  Certainly  it  will  be  evident  from  a  study 
of  the  forms  and  variations  of  pulp-canals  (see  Chapter  VIII.)  that 
only  pastes  or  fluids  can  fill  perfectly  all  of  the  irregular  spaces  found 
in  pulp-canals. 

Paraffin  fulfils  all  of  the  conditions  required  of  a  correct  canal- 
filling.  In  using  this  material  a  small  piece  is  caught  between  the 
jaws  of  a  pair  of  Flagg's  dressing-pliers  and  held  over  a  flame  until 
melted ;  then  the  closed  beaks  are  placed  as  high  up  the  canal  as 
they  will  go,  and  slowly  withdrawn  ;  gradually  opening  the  beaks,  the 
fluid  runs  up  the  canals  of  even  upper  teeth.  A  warm,  smooth  probe 
is  then  used  to  pump  the  fluid  paraffin  into  all  parts  of  the  canal.  Into 
the  fluid  paraffin  a  long  slender  metallic  point  of  some  unoxidizable 
material — gold,  platinum,  or  aluminum — is  warmed  and  thrust.  The  end 
of  the  metallic  point  is  left  projecting  into  the  pulp-chamber,  so  that 
should  removal  of  the  canal-filling  ever  become  necessary,  a  hot  instru- 
^  See  American  Text-book  of  Operative  Dentistry. 


DEVITALIZATION  OF  THE  DENTAL  PULD.  377 

ment  may  be  laid  against  its  exposed  end,  melting  the  paraffin,  when  the 
point  may  be  withdrawn. 

Accidents  -with  Arsenic. — If  arsenic  trioxid  come  in  contact  with 
any  vital  tissne,  it  exercises  its  destrnctive  inflnence  npon  it.  The 
most  common  accident  is  the  oozing  of  arsenic  from  beneath  a  seal- 
ing application,  and  its  contact  with  gum-tissne.  The  effect  of  the 
arsenic  in  these  cases  depends  npon  the  point  of  lodgement.  Arsenic 
trioxid  being  insoluble  in  the  fluids  of  the  mouth,  may  remain  lodged 
in  a  minute  crypt  and  exercise  its  destructive  influence.  Accidents  in 
this  direction  should  be  guarded  against  by  carefully  pressing  away  the 
gum  from  cavities  prior  to  using  the  arsenic ;  by  using  a  very  minute 
portion  of  the  latter  and  placing  it  with  precision  ;  by  the  use  of  small 
pieces  of  devitalizing  fibre  instead  of  paste.  Oozing,  however,  should 
never  occur,  and  when  it  does,  it  is  evidence  of  lack  of  care,  or,  worse, 
of  gross  carelessness  upon  the  part  of  the  operator. 

Arsenical  applications  sealed  in  with  any  material  other  than  zinc 
phosphate  should  be  examined  at  the  end  of  twenty-four  hours  to  see 
that  there  is  no  evidence  of  irritant  poisoning  of  the  soft  tissues.  The 
evidences  of  the  presence  of  arsenic  in  contact  with  gum-tissue  are  : 
deep  purple  engorgement  of  the  gum  and  subsequent  sloughing  of  the 
poisoned  tissue.  If  a  portion  of  the  arsenic  gain  lodgement  far  beneath 
the  gum-margin,  near  the  pericementum,  it  may  exercise  its  necrotic 
effects  upon  the  latter  tissue,  destroying  it  in  part  or  in  whole.  Flagg 
has  recorded  cases  in  which  necrosis  of  the  contiguous  alveolar  process 
has  occurred. 

The  only  cure  of  the  condition  consists  in  the  thorough  removal  of 
every  particle  of  the  arsenic.  Being  insoluble,  it  must  either  be  washed 
away  mechanically  or  be  transformed  into  a  soluble  or  an  inert  body. 
The  swollen  gum-tissue  is  to  be  pressed  away  from  the  tooth  and  jets  of 
warm  water  thrown  forcibly  into  the  space  in  the  hope  of  dislodging 
and  washing  away  the  insoluble  arsenic.  A  freshly  prepared  mass  of 
ferric  hydrate  (the  antidote  of  arsenic),  made  by  adding  magnesium  oxid 
to  ferric  chlorid,  may  be  packed  into  the  pocket,  but  its  utility  is  ques- 
tionable. The  free  use  of  iodin  tincture  in  one  case  appeared  to  give 
good  results,  perhaps  from  the  formation  and  washing  away  of  arsenic 
iodid.  Any  projecting  masses  of  oedematous  gum  should  be  cut  away,  as 
they  are  dead  and  will  slough  at  any  rate,  and  a  freer  access  to  deep 
parts  is  had — the  blood-flow  may  itself  wash  away  the  arsenic.  The 
forcible  washing  should  be  prolonged  and  repeated.  The  tissue  to 
Avhatever  extent  it  has  been  devitalized  by  the  arsenic  Avill  slough  away. 
Dental  literature  contains  the  records  of  a  few'  cases  in  which  the 
action  of  arsenic  has  extended  beyond  the  ends  of  the  roots  of  teeth, 
when  an  arsenical  application  has  been  made  iar  up  a  canal  to  destroy 


378  CHRONIC  DEGENERATIONS  OF  THE  PULP. 

a  vital  pulp-filament.  One  case  is  recorded  where  an  application  was 
carried  bodily  beyond  the  apex  of  the  root.  The  records  of  these  cases 
are  not  sufficiently  clear  to  formulate  rules  as  to  the  extent  of  destruc- 
tive action  caused  by  minute  portions  of  arsenic.  A  priori,  they  would 
be  governed  by  the  amount  of  arsenic  which  gains  access  to  the  peri- 
cementum ;  certainly  more  or  less  alveolar  necrosis  would  be  the  natural 
result.  The  insertion  of  a  broach  into  and  beyond  an  arsenical  appli- 
cation high  up  in  the  root,  into  the  apical  foramen  or  beyond,  may  no 
doubt  account  for  rare  cases  of  uncontrollable  pericementitis,  ceasing^ 
only  with  the  loss  of  the  tooth,  and,  it  may  be,  of  contiguous  bone. 

PARTIAL   REMOVAL   OF   PULP. 

The  cobalt  method  of  pulp-treatment  has  been  alluded  to.     Wm. 
Herbst,  of  Bremen,  advanced  the  idea  that  if  the  bulbous  portion  of 
the  pulp  be  devitalized  by  cobalt  and  removed,  leaving  the  root-portions, 
the  latter  will  remain  vital,  if  protected  after  a 
Fig.  294.  manner  described  by  him.     The  bulbous  portion 

of  the  pulp  is  cut  away  and  the  pulp-chamber  en- 
larged by  means  of  large  rose  burs.  Over  the  pulp- 
stumps  a  cylinder  of  tin-foil  is  laid,  and  burnished 
to  fit  the  floor  of  the  pulp-chamber,  without  pressure 
upon  the  pulp-stumps  (Fig.  294).  Over  this  a  fill- 
ing is  placed.  Herbst  claims,  endorsed  by  B5- 
decker,'  that  the  pulp-stumps  will  remain  vital. 
Were  this  to  be  depended  upon,  it  would  be  a  marked  saving  of  time 
and  trouble,  and  would  lessen  the  chances  of  pericementitis  subsequent 
to  pulp-removal ;  butwhen  it  is  known  that  the  cobalt  of  Herbst  is  metal- 
lic arsenic,  the  ultimate  death  and  decomposition  of  the  pulp-remnants, 
seem  almost  inevitable. 

MUMMIFICATION     OF    THE    PULP. 

As  early  as  the  introduction  of  arsenious  oxid  as  a  devitalizing- 
agent  it  was  noted  that  a  certain  percentage — or,  rather,  an  uncertain 
percentage — of  cases  gave  evidence  of  little  or  no  disease  after  the 
application  of  arsenic  and  its  sealing  in  a  cavity  by  filling.  Later,  it 
was  found  that  applications  of  powerful  antiseptics  to  exposed  pulps 
not  infrequently  were  followed  by  a  long-continued  quiet  of  that  organ ; 
still  later,  when  more  definite  knowledge  was  possessed  of  the  pathologi- 
cal results  which  might  follow  the  leaving  of  portions  of  pulp-substance 
in  the  canals  of  teeth  after  devitalization  by  arsenic,  it  was  observed 
that  after  saturating  the  canals  with  creosote  or  zinc-chlorid  solutions, 
^  Anatomy  and  Pathology  of  the  Teeth. 


MUMMIFICATION  OF  THE  DENTAL  PULP.  379 

many  cases  gave  little  or  no  evidence  of  pericemental  disturbance 
thereafter. 

While  it  is  unquestionably  preferable  to  always  thoroughly  remove 
the  last  vestige  of  devitalized  pulps,  the  time,  care,  skill,  and  expense 
involved  in  ])erfect  cleansing  are  drawbacks  to  its  universal  practice. 
The  only  other  possible  solution  of  the  difficulty  is  to  so  alter  the  tissue 
not  removed  that  it  shall  remain  permanently  aseptic,  and,  if  possible 
to  make  it  so,  antiseptic. 

Observations  derived  from  clinical  experience  although  undoubtedly 
of  great  and  permanent  value,  are  indeterminate,  and  our  truly  scientific 
knowledge  of  this  matter  dates  from  W.  D.  Miller's  experiments.^ 
He  credits  Witzel  with  the  first  systematic  observations  in  this  direction. 
Witzel,  in  1874,  "  devitalized  the  crown-portion  of  pulps  by  means  of 
arsenic,  extirpated  that  portion,  leaving  the  pulp  in  the  canals  undis- 
turbed, their  exposed  ends  being  treated  as  freshly  exposed  pulps." 
This  is  the  method  followed  by  Herbst,  who  employs  cobalt  (which  is 
native  arsenic  sulfid  or  metallic  arsenic)  instead  of  arsenic  trioxid. 

Miller's  experiments  have  shown  that  none  but  the  most  powerful 
and  penetrating  antiseptics  have  value  as  permanent  sterilizers.  These 
are  the  cyanid,  bichlorid,  and  salicylate  of  mercury,  sulfate  of  copper, 
and  oil  of  cinnamon.  Orthocresol,  carbolic  acid,  trichlor-phenol,  and 
zinc  chlorid  penetrate  the  pulp-tissue  rapidly,  but  are  too  diffusible,  dis- 
appearing in  a  few  weeks. 

He  classifies  salicylic  acid,  eugenol,  campho-phenique,  hydronaphthol, 
a-  and  /?-naphthol,  acetico-tartrate  of  aluminum,  and  some  essential 
oils,  resorcin,  thallin,  sulfocarbolate  of  zinc,  etc.,  as  being  of  doubtful 
value. 

Those  nearly  or  quite  worthless  are  iodoform,  basic  anilin  coloring- 
matters,  borax,  boric  acid,  dermatol,  europhen,  calcium  chlorid,  hydro- 
gen dioxid,  sozoiodol  salts,  tincture  of  iodin,  spirit  of  camphor,  and 
naphthalin. 

The  preparation  giving  the  best  results  consisted  of  mercuric  chlorid, 
0.0075  gram  ;  thymol,  0.0075  gram,  in  tablet-form. 

The  pulp  is  devitalized ;  the  crown-portion  and  all  the  root-portion 
readily  accessible  are  removed  ;  one  of  the  tablets  is  placed  in  the  pulp- 
chamber,  crushed  by  means  of  an  amalgam-plugger,  and  covered  with 
gold-foil.  The  mercury  salt  tends  to  discolor  the  crown  of  the  tooth, 
so  that  its  employment  should  be  restricted  to  the  posterior  teeth ; 
indeed,  the  necessity  for  its  use  would  be,  as  a  rule,  found  with  these 
teeth,  being  those  from  which  it  is  most  difficult  to  extract  pulp-rem- 
nants. Miller  expresses  faith  in  the  power  of  oil  of  cinnamon  to  per- 
manently  sterilize    pulp-fragments.      He    suggests    the    experimental 

^  Proc.  Columbian  Dental  Congress,  1893. 


380 


CHRONIC  DEGENERATIONS  OF  THE  PULP. 


application  of  the  sterilizing  tablets  to  such  teeth  as  are  readily  salvable, 
yet  which  are  for  various  reasons  "consigned  to  the  forceps." 

Theodore  Soderberg,  of  Sydney,  N.  S.  W.,  reports  excellent  results 
from  a  continuous  practice  of  this  method  of  pulp-sterilization.  He  em- 
ploys a  paste  composed  of — 


I^.  Alum  exsic, 
Thymol, 
Glycerol, 


Zi 


inc.  ox 


id. 


da.  3j  ; 
q.  s.  to  make  stiif  paste. — M. 


He  substitutes  dried  alum  for  tannin,  originally  used  by  him  as  the 
hardening-agent ;  his  experiments  showed  the  tannin  to  be  productive 
of  discoloration.  Mercuric  chlorid  is  set  aside  for  the  same  reason. 
Oil  of  cassia  employed  in  the  paste  also  caused  discoloration.  At  present 
Soderberg  adds  a  small  quantity  of  cocain  to  the  paste  to  prevent  the 
pain  arising  from  the  action  of  the  dried  alum.  He  states  (Nov.  1895) 
that  he  has  in  a  year  applied  the  paste  in  97  cases,  and  has  had  no 
untoward  results.  The  method  of  placing  the  material  is  shown  in 
Figs.  295  and  296. 


Fig.  295. 


Fig.  296. 


a,  caries  exposing  a  horn  of  the  pulp. 


a,  root-portion  of  pulp  ;  6,  mummifying  paste ; 
c,  zinc  phosphate  ;  d,  gold  or  amalgam. 


C.  A.  Firth,  of  Queenleyan,  N.  S.  W.,^  advises  the  omission  of  zinc 
oxid  from  the  paste,  to  avoid  the  formation  of  the  brown  tannate  of  zinc. 
He  suggests  the  use  of  a  mixture  of  tannic  acid  and  thymol,  equal  parts, 
made  into  a  paste  with  glycerol,  and  applied  with  ivory  instruments,  to 
avoid  discolorations.     He  expresses  himself  as  gratified  at  the  results 

obtained. 

^  Dental  Cosmos,  May,  1896. 


CHAPTER  XX. 
GANGRENE  OF  THE  PULP. 

Definition. — By  gangrene  of  the  pulp  is  meant  its  death  in  toto  from 
being  cut  off  from  its  nutritive  supply  at  the  apex  of  the  root.  It  occurs 
in  two  forms,  dry  and  moist.  Dry  gangrene  is  the  condition  known  as 
mummification  of  the  pulp.  Moist  gangrene  is  associated  with  putre- 
factive decomposition  of  the  organ.  The  conditions  differ  not  only  as 
to  causation,  pathology,  and  morbid  anatomy,  but  in  their  effects  and 
treatment,  so  that  each  requires  separate  consideration. 

Dry  Gangrene  of  the  Pulp. 

Definition. — By  dry  gangrene  of  the  dental  pulp  is  meant  its  death 
in  toto  and  its  subsequent  transformation  into  a  dry,  shrivelled  mass 
occupying  the  j)ulp-chamber  and  canal. 

Causes. — The  causes  of  this  condition  may  be  divided  into  physical 
and  chemical.  The  physical  causes,  so  far  as  known,  are  direct  injury 
or  jugulation  of  the  vessels  of  the  pulp  at  the  apical  foramen.  This 
may  be  due  to  blows  upon  the  teeth,  to  their  rapid  movement  in  regu- 
lating, particularly  by  their  forcible  movement  by  forceps,  to  too  sud- 
den and  violent  wedging,  and  by  non-fixation  of  the  teeth  during  and 
subsequent  to  regulating,  permitting  their  undue  movement ;  by  any 
force,  in  short,  which  can  cause  torsion  or  tension  of  the  vessels  at  the 
apex  of  the  root.  These  influences  acting  upon  the  apical  vessels  may 
cause  strangulation,  and  if  the  access  of  air  and  organisms  be  impossible 
or  does  not  occur,  the  watery  parts  of  the  pulp  may  be  removed,  leaving 
the  organ  as  a  tough,  shrivelled  mass. 

The  chemical  causes  include  the  action  upon  the  pulp  of  agents 
which  have  either  the  power  to  devitalize  it  and  preserve  it,  or  which 
transform  it  into  a  dry,  shrivelled,  and  aseptic  mass  after  its  death. 

Nearly  all  recorded  cases  appear  to  have  followed  the  employment 
of  zinc  oxychlorid  as  a  pulp-capping  or  a  cavity-lining. 

Patholog-y  and  Morbid  Anatomy. — Upon  opening  a  pulp-chamber 
containing  a  mummified  pulp  no  odor  is  emitted,  and  the  pulp  is  seen 
dark,  dry,  and  shrivelled.  In  cases  of  pulp-death  under  oxychlorid 
caps  it  is  difficult  or  impossible  to  determine  whether  the  pulj)  has 
been  killed  by  the  zinc  chlorid  and  preserved  by  absorption  of  that 
substance,  or  whether  it  has  died  from  other  causes  and  the  zinc  salt 

381 


382  GANGRENE  OF  THE  PULP. 

has  acted  as  a  preservative.  Certainly  the  condition  does  not  appear 
to  be  recorded  in  connection  with  other  capping-materials,  although 
other  antiseptics,  such  as  those  described  under  the  head  of  mummi- 
fying pastes,  might  undoubtedly  produce  similar  conditions. 

Symptoms. — Unless  secondary  processes  arise,  mummified  pulps 
give  rise  to  no  symptoms,  and  the  existence  of  the  condition  is  usually 
discovered  by  accident.  Their  usual  history  is  as  follows  :  at  a  previous 
time  (perhaps  years  before),  an  exposed  or  almost  exposed  pulp  has 
been  covered  with  a  cap  or  cavity-lining  of  the  oxychlorid  of  zinc,  and 
remained  comfortable  thereafter.  At  some  subsequent  time  it  may  be 
necessary  to  open  the  tooth,  usually  on  account  of  recurring  caries  :  the 
total  absence  of  dentinal  sensitivity  is  noted  ;  the  tooth  has  changed 
color  but  little,  if  at  all ;  and  the  operator  burs  carefully  toward  the 
pulp  to  determine  its  condition.  (It  should  be  remarked  here  that 
absence  of  dentinal  sensitivity  in  a  tooth  having  normal  color  and 
which  contains  a  very  large  filling  is  an  indication  of  aseptic  death  of 
the  pulp,  and  the  operator  should  renew  all  of  his  antiseptic  precautions 
as  to  isolation  of  the  tooth  by  the  rubber-dam  and  complete  sterilization 
of  all  instruments,  and  of  the  territory  of  operation.)  The  burring  is 
continued  without  any  evidence  of  sensitivity,  and  the  instnnnent  is 
fiually  felt  to  pass  into  the  pulp-chamber.  There  is  no  odor,  no  escape 
of  fluid  ;  the  pulp  is  found  dry  and  shrivelled.  If  sterilized  pulp- 
extractors  are  passed  into  the  canals,  the  remnants  of  the  pulp  may 
be  withdrawn,  exhibiting  none  of  the  usual  signs  of  decomposition, 
such  as  odor  and  confluent  softening. 

Treatment. — The  treatment  consists  in  aseptic  cleansing  and  her- 
metical  sealing  of  the  pulp-canal.  If  the  fluids  of  the  mouth  be  per- 
mitted access  to  the  mummified  pulp,  infection  occurs  promptly,  and  a 
vigorous  pericementitis  may  be  lighted  up.  Whether  the  dried  pulp 
aflcjrds  a  favorable  breeding-ground  for  particularly  virulent  organisms, 
or  whether  the  apical  pericementum  in  such  cases  affords  a  most  suitable 
field  for  their  secondary  activity,  certainly  the  pericementitis  which 
sometimes  follows  the  septic  opening  of  such  cases  is  pecuharly  obsti- 
nate. In  any  tooth  which  has  not  suffered  any  change  of  color,  in 
which  dentinal  sensitivity  is  entirely  absent,  and  which  was  believed 
to  contain  a  vital  pulp,  precautions  as  to  asepsis  and  antisepsis  should  be 
redoubled.  The  general  rule,  that  no  pulp-chamber  should  be  deliber- 
ately opened  before  adjusting  the  rubber-dam,  has  here  an  increased  sig- 
nificance. Every  bur  that  is  used  should  be  thoroughly  sterilized  before 
using.  As  soon  as  the  pulp-chamber  is  opened,  that  cavity  is  explored. 
A  clean,  new  broach  which  has  been  dipped  in  carbolic  acid  is  carried 
to  the  apex  of  the  root  and  withdrawn  ;  if  the  pulp  be  mummified,  the 
broach  brings  it  away  and  exhibits  no  fluid  upon  it.     If  any  deposits 


MOIST  GANGRENE  OF  THE  PULP.  383 

are  found  on  tlie  broach,  it  is  evidence  that  some  deconij)<)sition  has 
occurred.  The  at^ent  indicated  in  that  event  is  one  whicii  will  effec- 
tually destroy  all  organisms  which  might  be  present  and  whicli  will 
chemically  decompose — transform  into  soluble  and  entirely  removable 
substances — the  products  of  decomposition.  Sodium  dioxid  is,  therefore, 
the  indication.  It  may  be  used  in  50  per  cent,  solution  pumped  into 
the  canals  by  means  of  aluminum  or  iridium  broaches.  After  several 
applications  of  the  sodium  dioxid  solution  have  been  made,  the  canals 
are  to  be  washed  out  with  a  10  per  cent,  solution  of  hydrochloric  or 
sulfuric  acid  and  dried. 

No  matter  what  precautions  are  taken,  the  possibility  of  infection 
must  always  be  borne  in  mind.  While  pericementitis  usually  appears 
promptly  in  these  cases,  if  infection  have  occurred,  it  may  not  arise  for 
two  or  more  days  ]  during  this  period  it  is  advisable  to  insert  a  pro- 
bationary filling,  one  whicli  can  readily  be  removed  if  pericementitis 
does  arise.  This  filling  may  be  a  mixture  of  salol  and  aristol,  paraffin 
and  aristol,  or  a  twist  of  cotton  saturated  with  one  of  the  antiseptic  oils, 
such  as  cassia  oil.  In  all  cases  where  incomplete  mummification  of  the 
pulp  is  suspected,  it  is  a  wise  precaution  to  seal  in  the  cavity  a  5  per  cent, 
solution  of  formalin  f  )r  a  day  or  two  before  broaching,  to  give  assurance 
of  complete  sterilization. 

Moist  Gangrene  of  the  Pulp. 

Definition. — By  moist  gangrene  of  the  pulp  is  meant,  the  death  of 
the  pulp  en  masse  and  its  subsequent  decomposition  by  the  action  of 
putrefactive  agencies.  As  putrefactive  decomposition  is  the  essential 
feature  in  these  cases,  and  that  which  gives  the  process  its  pathological 
significance,  the  causes,  nature,  effects,  and  treatment  of  putrefactive 
decomposition  of  the  pulp  are  included  under  this  sub-heading. 

Causes. — The  death  of  pulp-tissue  from  any  cause  and  its  infection 
with  the  bacteria  of  putrefaction.  The  cases  are  of  two  types — those  in 
which  decomposition  occurs  without  the  existence  of  an  opening  com- 
municating with  the  exterior  and  those  in  which  such  an  opening  exists. 
The  first  class  may  be  subdivided  into  those  in  which  decomposition 
occurs  subsequent  to  the  insertion  of  a  filling  which  hermetically  seals 
the  space  between  the  pulp  and  the  exterior,  and  those  in  which  the 
tooth  is  non-carious.  It  is  to  be  recognized  that  in  the  absence  of 
bacteria  putrefaction  cannot  exist.  By  putrefaction  is  meant  that  serial, 
progressive  decomposition  through  which  albuminous  substances  are 
finally  resolved  into  the  end-products,  hydrogen  sulfid  (II2S),  carbon 
dioxid  (CO^),  ammonia  (NH^),  water  (H.fi),  and  hydrogen  phosphid 
(PH3).  One  distinguishing  feature  of  the  process  is  the  evolution 
of  malodorous  gases. 


384 


GANGRENE  OF  THE  PULP. 


¥\G.   297. 
Pigment.    S  +  hsemoglobin. 


Cases  of  Open  Cavities. 

When  the  pulp  of  a  tooth  is  exposed  and  becomes  the  seat  of  that 
series  of  vascular  and  nutritive  disturbances — hypersemia,  inflammation, 
and  suppuration — eventuating  in  its  gradual  death,  the  necrotic  portions 
undergo  putrefactive  decomposition.     Several  processes  are  in  operation 

at  the  same  time,  so  that  different  por- 
tions of  the  pulp  exhibit  differences  in 
chemical  composition,  differences  in  the 
nature  of  the  infection,  and  also  in  the 
pathological  conditions  existing.  For 
example,  while  the  apical  portion  of  the 
pulp  is  the  seat  of  inflammation  and  sup- 
puration, the  portion  of  the  pulp  pre- 
viously destroyed  through  these  pro- 
cesses, is  the  seat  of  later  stages  of  chem- 
ical destruction,  until  that  portion  which 
was  first  acted  upon  is  being  resolved 
into  the  end-products  of  albuminous  de- 
composition, of  putrefaction  (Fig.  297). 
In  this  serial  decomposition  albuminous 
substances  are  first  transformed  into 
peptones  and  allied  substances,  some 
of  them  being  very  toxic.  Compound 
ammonias,  known  as  ptomai'ns,  or  ani- 
mal alkaloids,  are  probably  next  formed. 
Next  the  nitrogenous  bases — leucin, 
tyrosin  and  the  amins  (methyl,  ethyl, 
and  propyl) — make  their  appearance 
together  with  organic  fatty  acids.  Next 
aromatic  products,  indol,  ph6nol,  cresol,  etc.,  and  finally  hydrogen  sulfid, 
ammonia,  carbon  dioxid,  and  water.  By  alternating  processes  of  hy- 
dration, reduction,  and  oxidation,  bodies  of  increasing  simplicity  of 
chemical  composition  are  formed.^ 

Miller^  found  in  the  deepest  portions  of  the  degenerating,  putrefying 
pulps,  where  inflammation  and  suppuration  were  in  progress,  a  pre- 
ponderance of  small  cocci  and  diplococci,  and  proceeding  toward  the 
open  pulp-chamber  an  increasing  number  of  large  cocci,  several  forms 
of  bacilli,  vibrios,  and  other  spirillse,  spirochsetse,  and  long  thread- 
forms  (Figs.  298-305).-  Figs.  304  and  305  are  from  the  same  pulp ; 
Fig.  305  was  taken  from  the  radicular  portion  of  a  pulp  which  was 
alive  and  suppurating;  Fig.  304  was  from  the  putrid  crown-portion. 
^  Ziegler's  General  Pathology.  2  j^^^ifji  Cosmos,  1894. 


COo,  NH3; 
H2O  and  H2S 


Aromatic  and 
fattj'  prod- 
ucts. 


CASES  OF  PUTREFACTION  UNDER  FILLINGS. 


385 


Until  infection  of  the  pericementum  occurs  these  cases  give  rise  to  no 
symptoms,  except  odor. 

Fig.  298. 


( -o.S^j^ 


Fig.  299. 


Fig.  300. 


I 


Fig.  301. 


'^l 


c^o         <»"»^ 


Fig.  303. 


Fig  304. 


Fig.  305. 


m^- 


'*1J 


r 


/?r/ 


f 
X 


/* 


r.'  / 


Cases  of  Putrefaction  under  Fillings. 

When  a  filling  is  placed  over  an  infected  pulp,  or  when  the  pulp 
dies  subsequent  to  the  insertion  of  a  filling,  the  organ  undergoes 
decomposition,  the  decomposition  being  carried  on  in  this  instance 
Avithout  the  access  of  air — /.  e.,  is  accomjjlished  by  anaerobic  organ- 
isms. Miller  found  that  bacteria  of  pulp-putrefaction  cultivated  in 
gelatin,  with  and  without  the  access  of  air,  exhibited  a  difference  in 

25 


386  GANGRENE  OF  THE  PULP. 

the  poisonous  properties  of  their  products.  Those  developed  with 
free  access  of  air  produced  stronger  reaction,  and  more  extensive  sup- 
puration than  those  developed  without  the  access  of  air. 

Symptoins. — Prior  to  infection  of  the  pericementum,  pulp-putre- 
faction occurring  under  fillings  may  give  rise  to  much  pain.  First,  in 
chronic  abscess  of  the  pulp,  by  imprisonment  of  the  pus.  Heavy,  throb- 
bing pain,  indefinitely  located,  may  be  felt,  and  the  tooth  may  be  tender 
upon  percussion  (see  Suppuration  of  Pulp).  Applications  of  heat  are 
almost  invariably  followed  by  a  paroxysm  of  pain  ;  the  gases  of  putre- 
faction being  expanded  by  heat,  exercise  pressure  upon  the  still  vital 
portions  of  the  pulp  and  upon  the  pericementum  ;  as  regards  the  latter 
tissue,  however,  it  is  probable  that  poisonous  products  are  by  the  expan- 
sion of  gases  forced  into  it.  The  relief  from  pain  is  in  some  cases 
almost  instantaneous  when  an  opening  is  made  into  the  pulp-chamber, 
giving  vent  to  the  imprisoned  gases. 

Oases  of  Pulp-putrefaction  without  Previous  Caries. 

Under  the  head  of  dry  gangrene  were  described  several  varieties  of 
traumatism  which  caused  the  death  of  a  tooth-pulp  en  masse,  particu- 
larly in  single-rooted  teeth.  Instead  of  becoming  mummified,  the 
necrotic  pulp  may  undergo  putrefactive  decomposition.  It  can  only  be 
a  matter  of  conjecture  how  the  organisms  necessary  to  putrefactive 
decomposition  gain  access  to  the  pulp.  The  possibility  that  organisms 
may  make  their  way  through  the  cementum  and  dentin  at  the  neck 
of  the  tooth  must  be  admitted,  although  its  extreme  improbability  must 
be  recognized.  The  more  probable  explanation  of  their  presence  is  that 
they  have  gained  access  to  the  circulation  from  some  other  portion  of 
the  body,  and  have  been  deposited  in  the  dead  pulp,  and,  finding  there 
a  suitable  soil,  have  developed. 

In  one  class  of  cases  the  source  of  infection  is  evident.  In  cases 
of  phagedenic  pericementitis  (which  see)  the  degeneration  of  the  peri- 
cementum may  open  a  direct  passageway  from  the  mouth  to  the  tissues- 
of  the  apical  space ;  the  pulp  is  cut  off  from  its  vascular  and  neural 
connections,  dies,  and  undergoes  putrefaction.  This  condition  may  be 
noted  upon  upper  molars  particularly,  where  the  pericemental  degenera- 
tion has  involved  the  apical  tissues  about  the  palatal  root  of  the  tooth; 
upon  opening  the  pulp-chamber  the  pulp  is  found  dead  and  putrefying 
in  whole  or  in  part. 

Many  of  these  cases  offer  no  subjective  evidences  of  disturbance, 
attention  being  directed  to  the  tooth  by  a  growing  opacity  of  the  dentin. 
A  reaction  occurs  between  the  hydrogen  sulfid  and  decomposing  haem- 
oglobin (hsemosiderin)  of  the  red  blood-corpuscles,  forming  dark  com- 
pounds, which  infiltrate  and  discolor  the  dentin,  rendering  it  opaque. 


CASES  OF  PULP-PUTREFACTION  WITHOUT  PREVIOUS  CARIES.    387 

In  other  cases  infection  of  the  pericementum  may  occur,  leading  to 
chronic  pus-formation,  with  an  exit  near,  or  in  many  cases  far  distant 
from  the  tooth. 

A  confusing  condition  clinically  is  found  where  one-half  of  a  pulp 
has  died  and  undergone  decomposition,  as  in  lower  molars,  the  other 
half  remainino;  vital,  althouoh  the  seat  of  infection  and  in.flammatoi-v 
action.  So  far  may  this  condition  go,  that  abscess,  acute  or  chronic, 
may  be  present  upon  the  root  of  one  tooth  long  before  the  second  seg- 
ment of  the  pulp  has  succumbed.  The  diagnosis  of  such  cases  is  made 
by  obtaining  the  jiainful  reaction  to  heat,  and  usually  some  tenderness 
upon  percussion  upon  some  particular  portion  of  the  tooth  ;  upon  open- 
ing the  tooth  the  peculiar  condition  described  is  formed. 

Treatment. — The  general  principle  of  treatment  is  the  same  in  all 
of  these  cases,  no  matter  to  what  clinical  division  they  may  belong — 
the  disinfection  of  the  canals,  the  removal  of  all  decomposed  and 
decomposing  pulp-tissue,  prevention  of  infection  of  the  pericementum, 
and  hermetical  sealing  of  the  apex  of  the  canal. 

In  all  of  the  cases  the  imminent  danger,  and  that  to  be  guarded 
against,  is  to  avoid  mechanically  carrying  a  portion,  ever  so  minute,  of 
infective  material  past  the  apical  foramen.  There  is  but  one  %vay  to 
accomplish  this  end  with  certainty,  and  that  is  to  render  the  contents 
of  the  canal  absolutely  non-infective  before  mechanical  procedures  are 
instituted.  This  implies  the  use  of  an  antiseptic  which  will  gradually 
diifuse  through  the  putrefying  mass  to  the  apex  of  the  root,  and  one 
which  is  certainly  germicidal.  The  condition,  as  shown,  is  one  of 
infection  to  near  the  apex,  so  that  any  pressure  exerted  upon  the  putrid 
mass  may  force  organisms  or  their  waste-products  through  the  apex  of 
the  root.  Many  antiseptics  have  been  shown  to  have  the  desired  power  ; 
notably  the  essential  oils  of  thyme  and  cinnamon  ;  carbolic  acid  and 
other  coagulating  agents  are  less  diffusible,  hence  less  prompt  and  cer- 
tain in  action  ;  lysol,  an  allied  substance,  is,  however,  much  more  dif- 
fusible. Of  all  present  antiseptics  solutions  of  formalin  are  perhaps 
most  effective  because  most  diffusible. 

The  first  step  of  operative  procedures  is  gaining  access  to  the  putrid 
pulp.  As  a  preliminary,  the  mouth  is  washed  with  antiseptics — hydro- 
gen dioxid,  potassium  permanganate,  or  meditrina — and  the  rubber-dam 
adjusted.  The  tooth  is  next  drenched  with  the  same  antiseptic  and 
partially  dried.  In  cases  of  open  cavity  loose  debris  is  lifted  away, 
without  exercising  pressure,  until  full  exposure  of  the  pulp-chamber  is 
secured.  A  pellet  of  cotton  saturated  with  meditrinia  (full  strength) 
laid  gently  upon  the  mass  deodorizes  it. 

Cases  of  putrid  pulp  under  fillings,  as  a  rule,  are  only  seen  when 
evidences   of  pericemental   disturbance   have   appeared.     Fissure-burs 


388  GANGRENE  OF  THE  PULP. 

are  passed  around  the  margins  of  the  filling  until  it  is  loosened  and 
detached,  and  free  applications  of  the  antiseptic  wash  made  until  free 
access  to  the  pulp-chamber  is  had. 

In  cases  without  cavities  or  fillings  a  spear-pointed  drill  is  passed 
by  the  most  direct  route  to  the  axis  of  the  pulp-canal.  The  drill  is  to 
be  advanced  gently,  so  that  it  will  not  plunge  forcibly  into  the  pulp- 
chamber.  In  all  of  these  cases,  as  soon  as  free  access  to  the  pulp-chamber 
is  secured,  a  drop  of  a  10  per  cent,  solution  of  formalin  is  flowed  into 
the  cavity  and  a  pellet  of  cotton  wet  with  the  same  solution  is  gently 
laid  over  it,  which  is  to  be  sealed  in  for  twenty-four  hours  by  means 
of  temporary  stopping. 

It  is  a  general  clinical  experience  that  in  the  cases  of  putrefying  pulp 
in  non-carious  teeth,  pericementitis  is  a  frequent  sequel  to  the  opening 
of  the  pulp-chamber.  This  has  been  attributed  to  the  entrance  of 
organisms  by  way  of  the  artificial  opening  made.  Other  reasons  for 
infection  would  be  the  access  of  air  to  the  previously  closed  cavity, 
favoring  the  development  of  virulent  organisms  already  present,  but 
inactive  on  account  of  an  absence  of  free  oxygen ;  or,  again,  the 
mechanical  forcing  of  infective  material  beyond  the  end  of  the  root. 
The  first  cause  is  scarely  probable  ;  the  second  more  probable  ;  and  the 
third  the  most  probable  cause  of  the  infection.  Presumptive  evidence 
of  this  is  found  where,  as  advised,  an  application  of  formalin  is  placed 
in  the  tooth  for  twenty-four  hours  before  any  attempt  is  made  at  the 
mechanical  cleansing  of  the  canals ;  subsequent  pericementitis  rarely 
occurs. 

To  remove  the  contents  of  the  canals  after  sterilization  no  agents 
act  with  such  promptness  and  effectiveness  as  solutions  of  sodium 
dioxid,  or  of  Schreier's  alloy  of  sodium  and  potassium — kalium- 
natrium.  The  reason  for  this  is  clearly  seen  from  a  study  of  the 
nature  of  the  substances  contained  in  the  canals,  and  the  reaction 
which  occurs  when  the  alkalies  mentioned  are  brought  in  contact 
with  them.  Brought  into  contact  with  agents  containing  water,  potas- 
sium-sodium immediately  causes  its  decomposition,  abstracting  HO, 
forming  sodium  and  potassium  hydrates  ;  hydrogen  is  set  free,  which 
ignites  in  consequence  of  the  heat  of  chemical  combination  set 
free  in  the  union  of  the  metals  with  hydroxyl.  Sodium  dioxid 
brought  in  contact  with  organic  matter  gives  up  its  extra  atom  of 
oxygen  to  the  latter  and  is  reduced  to  NgO?  sodium  oxid,  which,  com- 
bining with  water,  becomes  sodium  hydroxid.  Sodium  hydroxid  from 
either  source  saponifies  all  fatty  matters  and  dissolves  albumin  and  its 
derivatives.  The  action  of  sodium-potassium  is  very  pronounced  ;  a 
minute  portion  of  the  alloy  being  brought  into  contact  with  decom- 
posing organic  matter,  decomposes  its  water  with  such  activity  that  a 


TREATMENT  OF  MOIST  GANGRENE  OF  PULP.  389 

spark  is  produced.  The  gerniieidal  action  of  tlie  material  has  been 
attributed  to  this  heat ;  the  correct  explanation  is  probably  the  activity 
of  sodium  and  potassium  hydrates  in  their  freshly  formed  state.  The 
extra  atom  of  oxygen  in  sodium  dioxid  acts  as  a  prompt  antiseptic ; 
and  the  active  sodium  hydroxid  formed  fulfils  its  function  as  a  saponi- 
fying and  solvent  agent.  Sodium  dioxid  may  be  used  either  in  dry 
powder  or  in  saturated  solution  for  the  purpose  named. 

Non-oxidizable  metals  are  to  be  ]>referred  in  making  applications  of 
these  agents  ;  broaches  of  aluminum  or  of  iridio-platinum  answer  the 
purpose.  If  the  material  be  used  dry,  either  sodium-potassium  or 
sodium  dioxid,  the  roughened  broach  is  dipped  in  the  chemical  agent 
and  passed  part  way  up  the  canal  of  the  tooth  or  up  the  largest  canal 
in  multirooted  teeth ;  a  vigorous  reaction  immediately  occurs  between 
the  chemical  agent  and  the  canal-contents ;  as  soon  as  this  ceases  the 
canal  is  wiped  out  with  a  wisp  of  cotton  and  a  deeper  application  made. 
The  alternate  application  and  wiping  away  are  continued  until  the  apex 
of  the  root  is  reached.  By  this  time  the  walls  of  the  canal  are  seen  to 
be  distinctly  bleached  by  the  action  of  the  oxygen  set  free.  It  is  always 
to  be  remembered  that  this  decomposition  represents  a  chemical  reaction 
in  which  there  is  a  distinct  quantitative  relation  between  the  amount  of 
decomposer  and  dccomposible  matter  ;  an  excess  of  the  decomposer  is 
desirable  or  even  essential.  In  the  vast  majority  of  cases  an  error  is 
made  the  other  way.  The  operation  of  thoroughly  decomposing  the 
contents  of  a  pulp-canal  and  dentinal  tubuli  containing  decomposing 
albuminous  matter,  requires  a  considerable  length  of  time,  as  will  be 
seen  in  the  following  test.  After  having  spent  a  half  an  hour  or 
longer  in  carrying  successive  portions  of  the  active  agents  named 
into  pulp-canals,  say  of  a  lower  molar,  until  all  evidences  of  chem- 
ical reaction  cease,  then  forcibly  syringe  the  canals  wnth  hydrogen 
dioxid  or  a  10  ])er  cent,  hydrochloric  acid  solution  until  efferves- 
cence ceases ;  dry  the  cavity  and  canals,  insert  a  ball  of  cotton  in 
the  pulp-chamber,  leave  the  canals  unfilled,  and  seal  the  crown-cav- 
ity for  several  days ;  at  the  expiration  of  this  time  unseal  the  tooth, 
remove  the  cotton,  and  in  a  number  of  cases  the  odor  of  putrefaction 
may  be  detected.  The  sodium  oxid  solution  sloAvly  makes  its  way  into 
the  dentinal  tubuli,  decomposing  their  contents.  If,  now,  a  10  per  cent, 
solution  of  sulfuric  acid  be  pumped  into  the  canals,  it  effects  the  decom- 
position of  the  sodium  compounds  present,  forming  with  Xa^O^  ^ 

Ka,A  +  H.SO,  =  Xa^SO,  +  H,Oo, 

solutions  of  sodium  sulfate  and  hydrogen  dioxid,  which  in  its  turn  is 
^  See  Kirk,  American  Text-book  of  Operative  Dentistry. 


390  GANGRENE  OF  THE  PULP. 

decomposed  into  water  and  oxygen,  the  latter  driving  out  the  altered 
contents  of  the  tubuli.  Any  sodium  oxid  present  is  transformed  by  the 
sulfuric  acid  into  sodium  sulfate  and  water.  The  evidence  of  thorough 
action  of  the  sodium  dioxid  is  the  bleaching  of  the  dentin ;  dentinal 
walls  unbleached  are  evidence  of  incomplete  action  of  the  sodium 
compound. 

It  has  been  advised  by  many  operators  that  such  canals  be  immedi- 
ately and  permanently  filled,  as,  indeed,  they  may  be  in  very  many  cases, 
and  no  subsequent  trouble  arise.  It  is  the  part  of  prudence,  however, 
to  fill  the  canals  temporarily  until  it  is  seen  that  no  infection  of  the  peri- 
cementum has  occurred.  During  the  period  of  probation,  the  canals 
are  to  be  filled  with  a  diifusible  antiseptic ;  oil  of  cassia  is  the  agent 
most  frequently  and  acceptably  used  for  this  purpose.  Salol  makes  an 
excellent  tentative  filling  in  such  cases  ;  it  is  combined  with  one-third 
its  volume  of  aristol  for  this  purpose.  It  is  melted  and  flowed  into 
the  canals  by  means  of  Flagg's  dressing-pliers,  and  while  fluid  a 
hot  cone  of  metal  is  thrust  into  the  fluid  mass.  The  canal-filling 
may  be  made  of  cotton-thread  dipped  in  an  antiseptic  oil,  if  pre- 
ferred. 

In  a  few  days,  or,  better,  a  week,  if  no  evidences  of  pericemental 
disturbance  appear,  in  excess  of  a  slight  and  transient  soreness,  the  tooth 
may  be  opened,  always  under  rubber-dam,  the  canals  cleansed,  dried, 
and  permanently  filled.  It  is  always  a  wise  precaution  to  place  25  per 
cent,  pyrozone  in  such  canals  for  five  minutes  or  longer  before  drying 
and  filling  the  canals.  Slight  pericementitis,  evidenced  by  tenderness 
of  the  tooth  uj)on  percussion,  may  immediately  follow  the  treatment  of 
canals  by  the  sodium  compounds,  caused  by  the  passage  of  a  minute 
portion  of  the  preparation  beyond  the  apical  foramen.  As  a  rule,  the 
irritation  is  but  transient,  and  is  soon  reduced  by  applications  of  a 
counter-irritant  upon  the  gum  of  the  affected  tooth — tr.  iodin,  tr. 
aconite,  and  chloroform,  in  equal  parts,  painted  on  the  gum.  More 
severe  reactions  indicate  active  pericementitis. 

Canals  containing  putrescible  material  which  are  too  fine  to  admit 
even  slender  broaches  are,  after  the  action  of  the  formalin  solution,  en- 
tered and  cleansed  by  means  of  the  sulfuric  acid  method.  Enlargement 
of  the  canals  and  destruction  of  the  putrefactive  matter  are  accomplished 
simultaneously. 

It  has  been  maintained  that  if  the  pulp-canals  could  be  lined  with, 
and  the  contents  of  the  dentinal  tubuli  be  transformed  into,  permanently 
antiseptic  material,  that  future  sepsis  would  be  rendered  impossible.^ 
L.  P.  Bethel,^  basing  his  procedures  upon  the  fact  that  dentin  impregnated 

^  Proc.  American  Dental  Association,  1896. 

*  Proc.  New  York  Institute  of  Stomatology,  1897. 


TREATMENT  OF  MOIST  GANGRENE  OF  PULP. 


391 


with  silver  nitrate  notably  resisted  or  prevented  the  })rogre.ss  of  dental 
caries,  conceived  that  if  the  same  a^ent  conld  be  made  to  permeate  the 
dentin  of  tooth-roots,  it  would  act  there  as  a  permanent  antisejitic  and 
prevent  future  putrefaction  and  bacterial  development.  The  tooth  is 
isolated ;  the  application  is  confined  to  })()steri()r  teeth  ;  the  danger  of 
dentinal  discoloration  through  the  reduction  of  the  silver  salt  is  too 
great  in  the  anterior  teeth,  and  is  only  designed  for  canals  of  such  size 
and  shape  that  mechanical  cleansing  and  filling  are  extremely  difficult. 
The  crown-cavity  is  to  have  its  walls  covered  with  wax  or  varnish  to  pre- 
vent the  passage  of  the  silver  nitrate  into  the  crown-dentin  ;  the  canal  is 
pumped  full  of  a  silver-nitrate  solution  (25  per  cent,  to  75  per  cent.),  a 
pellet  of  cotton  containing  the  same  solution  is  wrapped  around  the 
positive  electrode  of  a  cataphoresis  apparatus,  the  current  is  applied, 
and  the  silver  solution  is  driven  into  all  of  the  tortuosities  of  the  canal 
(Fig.  306).     The  silver  combines  with  the  contents  of  the  dentinal  tub- 


1.  Operated  on  in  the  mouth  with  a  50  per  cent,  solution  silver  nitrate.    Crown-cavity  protected 

from  discoloration  by  a  thin  coating  of  melted  wax. 

2.  Operated  on  in  the  mouth  with  a  75  per  cent,  solution  silver  nitrate.     Crown-cavity  protected 

with  wax. 

3.  Operated  on  in  the  mouth  with  75  per  cent,  solution  silver  nitrate. 

4.  Shows  perfect  lining  formed,  and  penetration  of  tlie  silver  nitrate  into  the  dentinal  tubuli. 

5.  Freshly  extracted  tootli  operated  on  outside  the  mouth.    The  crown  and  roots  were  filled  with 

decomposing  material  which  wa.s  not  removed,  the  electrode  and  nitrate  being  applied  to  the 
surface :  still  the  nitrate  permeated  the  canals.    Exposed  surfaces  of  both  canals  shown. 

6.  Operated  on  outside  of  mouth.    Foramen  on  inside  of  root. 

7.  Shows  penetration  in  flat  root  with  restricted  and  branching  root-canal.    Could  not  get  broach 

more  than  one-eighth  inch  into  canal. 
8   Operated  on  outside  of  mouth,  for  twelve  minutes,  attempting  to  force  the  silver  nitrate  through 

foramen  of  root. 
9.  Shows  returning  branch  of  canal  that  might  easily  be  left  unfilled. 


uli,  forming  silver  albuminate ;  the  nitric  acid  is  formed  at  the  posi- 
tive pole  (the  electrode),  giving  an  acid  reaction  to  the  canal-contents  ; 
the  acid  is  neutralized  with  ammonia.  Unless  a  very  high  voltage  be 
applied,  the  silver  does  not  penetrate  the  dentin  to  any  considerable 
depth  and  it  is  not  desired  to  have  it  do  so.  Crede's  experiments 
indicate  that  metallic  silver  acts  as  an  antiseptic  by  being  oxidized 
by  bacterial  products,  the  argentic  oxid  being  afterward  transformed 
into  antiseptic  salts  of  silver  by  bacterial  waste-products,  notably  by 
lactic  acid,  silver  lactate  being  formed. 


SECTION  V. 

DISEASES  OF  THE   PERICEMENTUM. 


CHAPTER  XXI. 
SEPTIC  APICAL  PERICEMENTITIS  (ACUTE). 

Classification. — The  dental  periosteum  and  ligament,  or  the  peri- 
cementum, is  the  seat  of  numerous  nutritive  and  functional  disturbances, 
which  may  be  grouped  according  to  their  causes  into  septic  and  non- 
septic. 

The  term  pericementitis  has  been  indiscriminately  applied  to  all 
affections  of  the  pericementum,  and  in  some  cases  erroneously,  for  in 
not  all  affections  of  this  structure  do  the  phenomena  of  inflammation 
appear.  However,  most  of  the  acute  and  chronic  degenerations  are 
accompanied  by  evidences  of  inflammation. 

Bodecker's  division  of  the  affections  of  the  pericementum  into  puru- 
lent and  non-purulent  is  misleading.  Cases  may  be  due  to  septic 
causes  without  pus-formation  ;  pus-formation  represents  but  one  form 
of  sepsis. 

The  most  convenient  clinical  classification  of  these  disorders  is  that 
offered  by  G.  V.  Black  :^  first,  diseases  of  the  pericementum  beginning 
at  the  apex  of  the  root ;  secondly,  those  beginning  at  the  gum-margin  ; 
thirdly,  those  beginning  in  some  intermediate  portion  of  the  pericemen- 
tum. These  may  again  be  divided,  according  to  their  causes,  into  septic 
and  non-septic.  Another  clinical  classification  would  be  into  localized 
and  general  disturbances — another  into  acute  and  chronic. 

Evidences  of  Pericemental  Disturbance. — It  was  noted  in  the  study 
of  the  diseases  of  the  dental  pulp  that  the  diagnostic  signs  of  pulp-dis- 
turbance were  exaggerated  or  diminished  response  to  thermal  stimuli ; 
reflected  instead  of  localized  pains  ;  and,  except  in  rare  cases  of  advanced 
degeneration,  no  tenderness  upon  percussion.  Disturbances  of  the  peri- 
cementum are  accompanied  by  entirely  different  symptoms  which  serve 
to  distinguish  between  them  and  diseases  of  the  pulp.  They  are,  in 
general,  tenderness  upon  percussion.     As  shown  by  Black,^  the  peri- 

'  American  System  of  Dentistry,  vol.  i.  ^  Ibid. 

.S93 


394  SEPTIC  APICAL  PERICEMENTITIS. 

cementum  is  the  touch-organ  of  the  tooth,  its  tactile  organ,  through 
which  a  tooth  locates  force  applied  to  the  tooth.  The  pains  of  peri- 
cemental disturbance  are,  therefore,  in  the  majority  of  cases,  exactly- 
localized,  instead  of  not  being  localized  as  in  the  case  of  the  pulp. 
A  tooth  tender  upon  percussion  has  its  pericementum  the  seat  of 
disturbance.  Most  cases  of  pericemental  diseases  are  accompanied 
by  vascular  reactions  ranging  from  an  increased  blood-flow  or  grades 
of  hypersemia,  to  pronounced  inflammation,  and  have  the  correspond- 
ing symptoms.  The  increased  volume  of  the  pericementum  causes 
the  protrusion  and  loosening  of  the  tooth,  heightened  sensitivity  being 
the  accompaniment.  As  the  vascular  supply  of  the  pericementum 
and  that  of  the  gum  are  in  a  degree  collateral  (see  Chapter  VIII.), 
evidences  of  vascular  engorgement  are  seen  in  the  gum  overlying  the 
affected  tooth.  Owing  to  the  altered  density  of  the  parts  surrounding 
the  tooth-root,  percussion  upon  the  tooth  elicits  a  different  sound  from 
that  observed  in  health — the  sound  is  dull.  The  general  symptoms 
of  pericemental  affections  are,  therefore,  tenderness  upon  percussion 
and  a  dull  percussion-note,  more  or  less  protrusion  and  looseness  of  the 
tooth,  and  a  deepening  of  the  local  gum  color. 

Diseases  of  the  Pericementum  beginning  at  the  Apex. 

Diseases  of  the  pericementum  beginning  at  the  apex  of  the  root  are 
of  two  classes,  septic  and  non-septic.  The  septic  cases  are  almost  in- 
variably the  sequel  to  disease  of  the  pulp,  namely  suppuration  and 
gangrene  ;  or  arise  in  consequence  of  infection  through  the  canals  of  pulp- 
less  teeth.  The  non-septic  cases  are  due  to  mechanical  and  chemical 
irritants,  and  in  rare  cases  to  undiscovered  causes. 

ACUTE    septic    APICAL    PEEICEMENTITIS — ACUTE    ALVEOLO-DENTAL, 

ABSCESS. 

Definition. — By  septic  apical  pericementitis  is  meant  a  condition  due 
to  the  entrance  and  the  multiplication  of  septic  organisms  in  the  apical 
pericementum.  The  condition  may  be  acute  or  chronic,  the  chronic 
cases  being  usually  a  sequel  to  an  acute  septic  pericementitis. 

Causes. — By  far  the  most  common  cause  is  infection  of  the  peri- 
cementum, in  the  last  stages  of  pulp-putrefaction,  by  pyogenic  organisms. 
In  the  last  stages  of  pulp-destruction  through  septic  processes,  it  is  usual 
to  find  that  evidences  of  pericementitis  exist :  the  tooth  is  tender  upon 
percussion,  is  loosened,  and  protrudes  slightly.  As  a  rule,  this  irrita- 
tion subsides  after  a  few  days.  Succeeding  this,  is  a  period  of  quiet, 
before  pronounced  septic  pericementitis  arises.  It  appears  as  though 
the  waste-products  of  the  bacteria  in  the  decomposing  pulp  acted  as 
irritants  upon  the  apical  pericementum,  and  that  by  the  formation  of  a 


DISEASES  OF  PERICEMENTUM  BEGINNING  AT  THE  APEX.     395 

barrier  of  new  tissue  the  pericementum  wus  temporarily  protected.  Its 
causes  are  found  in  all  of  the  conditions  under  which  moist  gangrene  of 
the  pulp  occurs. 

Purulent  apical  pericementitis  is  not  always  preceded  by  pulp-death 
and  putrefaction  ;  although  when  the  condition  arises  the  pulp,  if  alive, 
dies.  Considerable  purulent  destruction  of  the  pericementum  may  occur 
near  the  apex  of  the  root  and  the  pulp  of  the  tooth  remain  alive.  The 
path  of  infection  in  these  cases  is  unknown  ;  it  is  probably  identical 
with  that  of  pulp-putrefaction  in  cases  without  existing  or  previous 
caries.  The  possibility  of  infection  by  deposition  of  pyogenic  organ- 
isms which  have  found  their  way  into  the  circulation  from  other  parts 
of  the  body  must  be  admitted.  The  common  infective  organisms,  those 
which  predominate  in  purulent  apical  pericementitis,  are  the  pyogenic 
staphylococci.  Schreier '  stated  that  out  of  twenty  cases  he  had  found 
in  fifteen  a  diplococcus  which  he  termed  the  diplococcus  pneumoniae. 
Miller's  ^  experiments  failed  to  confirm  the  identity  of  the  diplococcus 
found  with  that  of  pneumonia.  Schreier's  studies  ^  exhibit  a  prepon- 
derance of  the  staphylococcus  pyogenes  albus  and  aureus,  diplococci, 
and  occasional  streptococci,  virtually  the  same  organisms  that  are  found 
in  the  deeper  portions  of  a  sup])urating  pulp  :  this  fact  in  itself  is 
enough  to  show  the  continuity  of  infection  from  the  pulp-canal.  It  is 
a  well-known  clinical  fact  that  acute  outbreaks  of  septic  apical  peri- 
cementitis are  most  liable  to  occur  under  those  conditions  when  patients 
"  take  cold."  Schreier  points  out  that  these  atmospheric  states  produce 
a  bodily  condition  which  favors  the  development  of  the  diplococcus 
pneumoniae,  and  finds  in  the  association  of  these  factors  the  reason 
why  this  diplococcus  should  be  pathogenic  in  the  dental  condi- 
tion. 

Morbid  Anatomy  and  Patholog-y. — The  general  morbid  anatomy 
of  this  condition  is  that  of  abscess,  modified,  of  course,  by  the  anatom- 
ical structure  of  the  part.  Pyogenic  organisms  gain  access  to  the  peri- 
cementum through  the  paths  named,  and  a  degree  of  inflammation  is 
excited,  governed  by  the  virulence  of  the  infection  and  the  condition 
of  the  patient.  An  abundant,  fibrinous,  coagulable  exudation  is  poured 
out  into  the  interstices  of  the  pericementum,  not  beneath  the  membrane 
— an  exudation  of  leucocytes  occurs  ;  the  pericementum  swells,  its  fibres 
at  and  about  the  apex  soften,  the  fixed  cells  of  the  tissue  undergo  prolif- 
eration, and  the  tooth  is  protruded  and  loosened.  The  inflammatory  cor- 
puscles are  killed  in  great  numbers  by  the  waste-products  of  the  organ- 
isms ;  the  exudation  is  peptonized — liquefied  by  ferments  excreted  by  the 
bacteria,  the  dead  corpuscles  being  also  broken  down  into  a  granular 
detritus.  The  inflammatory  process  extends  radially  from  the  focus  of 
1  Dental  Cosmos,  1893.  ^  jjj^^  i894.  '  Ibid. 


396 


SEPTIC  APICAL  PERICEMENTITIS. 


infection,  an  inflammatory  zone  preceding  the  death  and  disorganization 
of  corpuscles  and  eifusions.  The  destruction  of  tissue  proceeds  in  all 
directions,  advancing  most  rapidly  in  the  direction  of  least  resistance, 
until  the  abscess  reaches  the  surface,  points,  and  discharges  its  contents. 
From  the  pericementum  the  inflammation  extends  to  the  alveolar  bone, 
which  is  melted  down  molecularly  ;  thence  to  the  periosteum,  which 
undergoes  inflammatory  degeneration  ;  the  gum-tissue  is  next  involved, 

Fig.  307. 


Showing  the  morbid  anatomy  of  septic  apical  pericementitis  (acute) :  A,  pus ;  B,  area  of  dying- 
leucocytes  ;  C,  foreign  matter  in  root-canal ;  D,  excavation  of  process  (osteomyelitis) ;  E, 
swollen  periosteum  and  gum ;  F,  alveolar  bone ;  G,  pericementum  at  edge  of  necrosis. 


until  it  is  softened  and  perforated.  While  in  the  vast  majority  of  cases 
the  direction  taken  by  the  pus  and  the  point  at  which  it  finds  exit  is 
the  buccal  or  labial  aspect,  and  immediately  over  the  root-apex  of  the 
affected  tooth,  or  near  it,  these  being  the  directions  of  least  resistance, 
other  anatomical  conditions  or  histological  peculiarities  (see  Chapter 
VIII.)  may  make  the  direction  of  least  resistance  in  some  other 
path. 

Instead  of  the  circumscribed  suppuration  described  as  the  ordinary 
course  of  abscess-formation  about  the  apices  of  roots  (septic  apical  peri- 
cementitis) which  accompanies  infection  by  the  staphylococci,  clinical 
evidences  of  infection  by  a  streptococcus  occasionally  appear.  The 
inflammatory  process,  instead  of  being  circumscribed,  is  diffuse ;  the 
inflammation  extends  along  the  lines  of  connective  tissues  and  of 
lymphatics ;  the  connective  tissues  are  swollen,  the  swelling  extending 


DISEASES  OF  PERICEMENTUM  BEGINNING  AT  THE  APEX.     397 

to  the  tissues  of  the  cheek,  down  the  neck,  and  even  to  the  shoulder — 
a  phk'gmonous  inflamnuition.  Instead  of  the  comparatively  free  flow  of 
pus  which  follows  incision  of  the  swelling  in  ordinary  abscess,  pus-for- 
mation in  streptococcus  infection  is  seen,  upon  incision,  to  be  limited  and 
sero-purulent.  While  in  alveolar  abscess  of  the  ordinary  types  evidences 
of  septic  intoxication  or  poisoning  are  unusual,  the  lymphatics  being 
blocked,  as  a  rule,  by  the  inflammatory  exudation  ;  septic  intoxication 
and  poisoning  are  the  rule  in  the  erysipelatous  cases,  those  probably 
due  to  streptococcus  infection  ;  bacterial  poisons  being  taken  up  by  the 
lymphatics  find  their  way  into  the  circulation. 

After  spontaneous  discharge  of  the  pus  from  an  abscess,  the 
condition  remaining  is  that  of  an  ulcerous  surface  (the  abscess  boun- 
daries), which  is  being  continuously  infected  from  the  putrescent  pulp- 
remnants.  The  conditions,  it  is  seen,  are  not  like  those  of  ordinary 
abscess,  where  the  infective  material  is  largely  discharged  in  the  pus- 
evacuation,  and  the  cells  bounding  the  abscess-wall  dispose  of  remain- 
ing bacteria,  so  that  regeneration  of  tissue  occurs.  Spontaneous  healing 
of  an  alveolar  abscess  is  the  exception  ;  the  embryonic  tissue  lining  the 
abscess-walls  being  continuously  infected,  degenerates  and  dies  instead  of 
regenerating,  leaving  a  condition  known  as  chronic  alveolar  abscess,  or 
chronic  apical  septic  pericementitis  piirulenta. 

Symptoms. — According  to  the  severity  of  the  symptoms,  apical 
pericementitis  may  be  divided  into  several  grades,  each  of  which  repre- 
sents more  or  less  well-defined  pathological  conditions.  It  is  to  be 
remembered  that  the  normal  progress  and  outcome  of  this  condition 
are  toward  the  formation  and  evacuation  of  pus,  so  that  the  symptoms 
will  be  largely  governed  by  the  difficulty  or  readiness  with  which 
the  discharge  is  efl^ected.  Infection  represents  the  first  stage  of  the 
acute  disease,  pus-discharge  the  last,  after  which  the  acute  symptoms 
subside. 

The  first  symptom  to  ai)pear  is  tenderness  upon  percussion,  the  dis- 
ease being  ushered  in  by  an  active  hyperemia.  As  in  other  active 
hyperemias,  the  sensitivity  of  sensory  nerve-fibres  is  heightened  ;  if 
the  tooth  be  moderately  pressed  upon,  it  is  tender ;  but  if  forcibly 
pressed  upon — /.  e.,  the  apical  arteries  be  compressed — the  hyperseraia 
is  momentarily  lessened,  and  the  pressure  brings  a  sense  of  relief. 
This  period  is  succeeded  by  a  protrusion  of  the  tooth  beyond  its  fellows  ; 
it  appears  to  be,  and  is,  longer  than  the  other  teeth  ;  it  is  loosened  and 
becomes  very  sore  upon  pressure,  and  soon  tender  or  exquisitely  painful 
to  the  slightest  touch .  Throbbing  pain  now  occurs,  and  the  gum  overlying 
the  atfected  tooth,  first  heightened  in  color,  becomes  swollen  and  deeply 
colored.  These  conditions  correspond  with  the  exudation-period  of  the 
inflammation.     The  tooth  becomes  progressively  looser,  and  so  tender 


398  SEPTIC  APICAL  PEBICEMENTFnS. 

that  it  will  not  bear  the  slightest  touch  ;  the  throbbing  pain  increases 
in  severity,  and  the  gum-tissue,  and,  it  may  be,  the  tissue  of  the  cheek 
or  lip,  also  become  much  swollen.  The  swelling  of  the  gum,  at  first 
of  board-like  hardness,  softens  at  its  highest  point  ;  soon  a  yellow  spot 
appears,  the  mucous  membrane  bursts,  and  a  discharge  of  pus  follows. 
As  soon  as  softening  of  the  swollen  gum  occurs  the  excruciating  pain — 
an  acute  alveolar  abscess  is  one  of  the  most  painful  of  diseases — and 
the  tenderness  of  the  aifected  tooth  usually  diminish,  but  some  degree 
of  protrusion  and  loosening  remains. 

In  multirooted  teeth  the  inflammation  and  abscess  frequently  appear 
on  only  one  root.  If  the  case  be  seen  early,  before  the  active  exudation- 
period  of  the  inflammation  sets  in,  the  symptoms  may  be  clearly  localized 
in  one  root,  the  tooth  exhibiting  tenderness  upon  pressure  over  the  affected 
root,  but  not  upon  the  opposite  side. 

The  symptoms  above  described  are  those  of  average  severity. 
Variations  occur ;  some  cases  have  a  lesser  degree  of  intensity,  some 
a  higher  degree.  Pain  and  swelling  may  be  comparatively  slight 
and  pus-discharge  prompt.  In  other  cases  pain,  swelling,  and  loose- 
ness of  the  tooth  are  pronounced  at  an  early  period,  and  several 
grades  of  constitutional  disturbance  may  appear.  The  pulse  increases 
in  volume  and  tension,  the  tongue  is  coated,  and  the  temperature 
of  the  body  rises ;  the  rise  of  temperature  may  be  ushered  in  with 
a  distinct  chill — i.  e.,  a  condition  of  fever  is  present,  due  to  the 
absorption  of  bacterial  products.  As  a  rule,  these  general  symptoms 
accompany  the  cases  in  which  the  vascular  disturbance  is  widespread. 
Instead  of  the  swelling  extending  but  little  beyond  the  overlying  gum, 
the  tissues  of  the  lips,  cheeks,  or  neck  may  be  very  much  swollen  and 
the  eye  of  the  aff^ected  side  injected.  In  some  cases  the  outer  skin  may 
become  reddened  and  dusky,  exhibiting  the  evidences  of  extension  of 
the  inflammatory  process  far  from  its  original  site. 

Clinical  History. — As  shown  in  Chapter  VIII.,  the  apices  of  the 
roots  of  teeth  lie  nearer  to  the  external  alveolar  wall  than  to  the  inner, 
with  the  exception  of  the  palatal  roots  of  the  upper  molars  and  the 
roots  of  the  lower  molars,  the  ends  of  the  roots  in  some  cases  being 
covered  by  laminte  of  bone  of  extreme  thinness.  Apparently  the 
alveolar  periosteum  and  gum-tissue  vary  in  density.  Recognizing  these 
differences,  the  clinical  history  of  acute  alveolar  abscess  may  be  divided 
into  three  stages  :  first,  that  of  initial  inflammation  and  pus,-formation  ; 
secondly,  the  destruction  of  the  alveolar  process  ;  thirdly,  the  passage 
of  pus  through  the  periosteum  and  mucous  membrane.  The  second 
stage  is  usually  the  longest.  The  duration  of  the  disease  depends  upon 
the  readiness  with  which  the  tissues  between  the  point  of  beginning  pus- 
formation  and  its  exit  yield.     When  the  pulp-chamber  is  open  pus  may 


DISEASES  OF  PERICEMENTUM  BEGINNING  AT  THE  APEX.      399 


Fig.  308. 


find  exit  by  this  path,  constituting  the  condition  kno^yn  as  blind  abscess 
— a  misnomer,  because  a  blind  abscess  is  one  without  a  point  of  dis- 
charge, without  a  fistula  leading  to  it ; 
in  the  cases  discharging  via  the  canal, 
the  latter  may  be  considered  a  fistula. 

These  cases  usually  run  a  short 
course,  the  inflammatory  symptoms 
rarely  being  severe,  and  the  tissue-de- 
struction limited  (Fig.  308).  Notably 
upon  lower  molars,  and  upon  the  pa- 
latal roots  of  upper  molars,  the  dens- 
ity and  thickness  of  bone  overlying 
the  roots  may  make  paths  of  greatly 
increased  resistance,  so  that  the  de- 
struction of  tissue  proceeds  along  the 
line  of  the  pericementum,  the  pus  finding 
exit  at  the  neck  of  the  tooth  (Fig.  310). 

It  is  rare  in  cases  of  lower  second  molar,  and  still  more  rare  upon  the 
third  molars,  that  pus  finds  exit  over  the  apex  of  the  root,  the  dense  bone 
of  the  external  oblique  line  (Fig.  309)  offering  the  greatest  resistance 


Blind  abscess  it  the  root  of  an  upper 
incisor:  a,  abscess-cavity  in  bone;  6, 
drill-hole  exposing  the  pulp-chamber 
for  treatment.     (Black.) 


Fig.  309. 


Fig.  310. 


Fig.  309.— Abscess  upon  lower  third  molar,  showing  the  usual  paths  of  pus-exit,  A  and  B. 
Fig.  310.— Abscess  upon  palatal  root  of  an  upper  molar  discharging  at  the  neck  of  the  tooth. 

Over  any  teeth  the  outer  fibrous  layers  of  the  external  periosteum 
may  offer  unusual  resistance  to  the  perforative  advance  of  pus,  so  that 
when  the  fibres  of  attachment  of  the  periosteum  have  been  softened  by 
the  inflammation,  and  pus  gains  entrance  between  bone  and  periosteum, 
it  may  travel  or  burrow  along  the  course  of  this  membrane  (Fig.  311), 
depriving  the  bone  of  its  main  nutritive  source,  so  that  limited  necrosis 
threatens.  The  roots  of  the  central  incisors  may  lie  unusually  close  to 
the  floor  of  the  nose,  and  be  overlaid  externally  by  an  unusually  resist- 
ant layer  of  bone ;  in  these  cases  the  path  of  least  resistance  may  be  in 


400 


SEPTIC  APICAL  PERICEMENTITIS. 


the  direction  of  the  floor  of  the  nose,  the  abscess  opening  at  that  point 
(Fig.  312). 

Fig.  311. 


Acute  alveolar  abscess  of  a  lower  incisor,  with  pus-cavity  between  the  bone  and  the  periosteum: 
a,  pus-cavity  in  the  bone;  6,  pus  between  the  periosteum  and  bone;  c,  lip;  rf,  tooth;  e, 
tongue.    (Black.) 

The  root-apices  of  the  posterior  upper  teeth,  particularly  of  the  first 
and   second   molars,  may  after   the  age  of  twenty-five   or  thirty  be 

Fig.  313. 


Fig.  312. — Alveolar  abscess  at  the  root  of  a  superior  incisor  discharging  into  the  nose:  a,  large 
abscess-cavity  in  the  bone ;  6,  mouth  of  fistula  on  the  floor  of  nostril ;  c,  lip ;  rf,  tooth. 
(Black.) 

Pig.  313. — Alveolar  abscess  at  the  root  of  an  upper  molar  discharging  into  the  antrum  of  High- 
more  :  a,  abscess-cavity  in  the  bone ;  h,  mouth  of  fistula  on  the  floor  of  the  antrum ;  c,  pus  in 
the  antral  cavity.     (Black.) 

encroached  upon  by  the  enlarging  maxillary  sinus,  so  that  any  or  all 
of  the  roots  of  these  teeth  may  be  separated  from  the  floor  of  the  sinus 


DISEASES  OF  PERICEMENTUM  BEGINNING  AT  THE  APEX.     401 

by  but  a  very  thin  lamina  of  bone  ;  .should  abscess  arise  upon  any  of 
these  roots,  pus-discharge  into  the  antrum  would  necessarily  follow 
(Fig.  313).  _  ^ 

Resort  to  the  use  of  poultices,  for  the  relief  of  the  pain  of  abscess- 
formation,  may  induce  such  a  softening  of  the  tissues  over  which  they 
are  applied,  that  the  passage  of  pus  is  invited  toward  the  exterior ;  the 
abscess  may  thus  open  upon  the  face  or  neck,  producing  permanent, 
disfiguring  scars. 

In  patients  who  are  in  a  cachectic  condition,  who  have  an  evil 
heredity,  or  whose  tissue-resistance  is  markedly  lessened  in  consequence 
of  tuberculosis,  or  more  frequently  of  syphilis,  septic  pericementitis 
may  run  a  riotous  course  ;  the  bone  suffers  extensively  by  direct  action  ; 
the  periosteum  is  undermined,  is  stripped  from  the  bone  over  large  areas, 
and  breaks  down  readily  ;  so  that  while  in  the  healthy  person  alveolar 
abscess-formation  may  run  a  direct  course  and  find  prompt  outlet,  in 
the  syphilitic  patient  extensive  pus-infiltration,  with  necrosis,  may  occur. 
In  cachectic  persons  lymphatic  involvement  is  common ;  waste-products 
of  bacterial  origin  find  their  way  into  the  lymphatics  and  set  up  sec- 
ondary irritative  processes  in  the  nearest  lymphatic  glands — lymph- 
adenitis. 

In  persons  whose  oral  hygiene  is  neglected  the  third  stage  of  alveolar 
abscess  is  frequently  violent  and  the  inflammatory  process  widespread. 

In  acute  abscess-formation  the  inflammatory  action  precedes  the 
advance  of  pus,  which  furnishes  a  guide  to  the  direction  the  pus  is 
pursuing  ;  viz.,  where  the  most  intense  coloration  and  the  greatest  swell- 
ing appear  will  he  the  ])oint  at  which  the  abscess  will  point  or  discharge. 
A  subsidence  of  inflammation  without  an  immediately  discoverable 
point  of  pus-exit  should  lead  to  the  suspicion  that  the  discharge  has 
taken  place  in  an  unusual  situation. 

Diagnosis. — If  a  tooth  have  been  the  seat  of  acute  septic  pericemen- 
titis of  high  grade  for  twenty-four  hours,  pus  has  almost  certainly 
formed,  and  its  presence  may  be  safely  diagnosed.  The  symptoms 
rarely  leave  any  doubt  as  to  which  tooth  is  affected,  except  where  two 
contiguous  teeth,  evidently  pulplcss,  are  both  loosened  and  surrounded 
by  a  zone  of  inflammation.  Even  in  these  cases  there  will  be  found 
differences  in  response  to  tapping  or  pressure  which  will  indicate  which 
tooth  is  the  disease-focus. 

Prognosis. — In  the  majority  of  cases  the  prognosis  of  acute  alveolar 
abscess,  as  to  the  future  retention  of  the  tooth,  is  favorable  ;  and  usually 
very  favorable,  if  the  case  receive  intelligent  therapeutic  aid.  The 
future  of  the  tooth  depends  upon  the  thoroughness  with  which  sources 
of  infection  may  be  destroyed  and  permanently  removed,  and  the  com- 
pleteness with  which  regeneration  of  tissue  can  be  induced. 

26 


402  SEPTIC  APICAL  PERICEMENTITIS. 

If  the  first  stage  of  abscess-formation  be  prolonged,  destruction  of 
pericementum  is  correspondingly  increased ;  a  prolonged  second  stage 
pauses  an  increased  molecular  destruction  of  alveolar  bone ;  a  prolonged 
third  stage  may  mean  stripping  of  the  periosteum  from  the  alveolar 
wall,  or  infiltration  of  pus  into  the  connective  tissue  of  the  lip  or 
cheek.  Marked  swelling  of  the  tissues  of  the  face,  with  an  increasing 
redness  of  surface,  leads  to  the  suspicion  of  pus-presence  and  the  danger 
of  its  external  discharge.  Rigors  and  fever,  appearing  during  the  course 
of  the  inflammation,  are  evidence  of  absorption  of  and  the  presence  in 
the  circulating  fluids  of  bacterial  products.  Repeated  rigors,  with  pro- 
nounced depression,  diarrhoea,  and  delirium,  indicate  that  pyaemia 
exists.  Delay  in  the  natural  evacuation  of  the  pus  should  lead  to  the 
suspicion  that  it  is  pursuing  an  unusual  course,  its  direction  being 
usually  determined  by  the  focus  of  inflammatory  action. 

Treatment. — The  first  principle  of  treatment  is  the  removal  of  the 
source  of  infection.  As  in  all  other  septic  diseases,  there  is  no  means  com- 
parable with  this  in  point  of  eflectiveness.  After  removing  the  source 
of  infection  the  symptoms  of  the  disease-process  subside  rapidly.  If  it  be 
not  removed  surgically,  the  disease  persists  until  the  pus  finds  vent,  when 
the  inflammation  subsides.  The  immediate  accomplishment  of  this  end 
may,  however,  be  impracticable  in  some  cases.  Recognizing  the  putres- 
cent pulp-canal  contents  as  the  source  of  infection,  primary  attention 
is,  of  course,  directed  toward  sterilization  and  removal  of  these  con- 
tents. If  the  case  be  seen  before  the  inflammatory  process  become  pro- 
nounced, entrance  to  and  cleansing  of  the  canals  can  usually  be  accom- 
plished. If  the  pulp-cavity  be  open  in  such  cases,  direct  approach  is 
made  to  the  canals  through  the  carious  cavity.  A  free  syringing  with 
strong  solutions  of  meditrina  precedes  the  opening  of  the  canals.  If  it 
be  a  filled  tooth,  and  the  filling  is  in  a  situation  that  by  an  opening  made 
through  it,  or  by  its  removal,  direct  access  to  the  canals  can  be  gained,  the 
opening  should  be  made.  The  opening  of  the  cavity  is  to  be  accomplished 
by  means  of  a  very  sharp  and  small  spear-point  drill  revolving  in  a  per- 
fectly true  hand-piece.  Large  drills,  ill-sharpened  and  in  worn  hand- 
pieces, produce  a  jarring  which  adds  notably  to  the  tenderness  of  the 
pericementum.  According  to  the  amount  of  tenderness,  the  tooth  will 
require  a  counter-pressure  to  that  of  the  drill.  If  the  entrance  be 
made  through  the  occlusal  face  of  the  tooth,  or  in  a  direction  which 
would  cause  direct  upward  pressure  on  the  apical  pericementum,  a  liga- 
ture of  linen  thread  with  long  ends  may  be  placed  around  the  tooth,^ 
and  traction  be  made  by  drawing  on  the  loose  ends  of  the  ligature. 
Effective  counter-pressure  against  lateral  entrance  to  the  pulp-chamber 
may  be  made  by  softening  a  small  roll  of  modelling  compound  and 
^  J.  Foster  Flagg,  Lectures  on  Dental  Therapeutics- 


DISEASES  OF  PERICEMENTUM  BEGINNING  AT  THE  APEX.     403 

moulding  over  the  face  of  the  affected  tooth  and  several  of  tliose  adjoin- 
ing- it,  and  permitting  it  to  harden.  This  temporary  splint  is  held  in 
place  by  the  index  linger  of  the  left  hand.  In  case  the  inflammatory 
process  is  marked,  it  is  frequently  necessary  to  make  a  vent-opening  by 
the  most  direct  path — /.  c,  at  the  junction  of  enamel  and  cementum — 
directly  into  the  chamber. 

As  soon  as  entrance  to  the  pulp-chamber  is  effected,  the  cavity  is 
syringed  with  a  strong  antiseptic ;  a  20  per  cent,  solution  of  meditrina 
answers  well  in  this  connection.  Fine  probes  are  paesed  and  repassed 
into  the  opening  to  free  the  outlet,  so  that  gases  may  escape  ^nd  fresh 
portions  of  the  antiseptic  be  worked  into  the  cavity.  The  quickness 
with  which  relief  is  secured  will  depend  upon  the  thoroughness  with 
which  the  canals  are  entered  and  their  putrid  contents  destroyed.  A 
tedious  class  of  cases  are  those  in  which  a  canal  of  a  molar  is  unfilled  or 
but  partially  filled.  Unless  entrance  to  and  cleansing  of  the  canal  be 
accomplished,  the  inflammation  will  proceed  until  the  pus  finds  external 
vent.  An  hour  spent  in  gaining  access  to  and  cleansing  such  canals  is 
well  spent. 

If  entrance  to  the  canals  is  free,  repeated  applications  of  sodium 
dioxid  solutions  should  be  made,  pumped  into  the  canals,  and  the  cavity 
washed  from  time  to  time  with  meditrina  or  hydrogen  dioxid.  Near 
the  end  of  the  canal  the  meditrina  is  used  alone  with  broaches,  and 
finally  by  syringing.  The  canals  are  dried,  and  an  anodyne  antiseptic, 
such  as  a  mixture  of  thymol  and  menthol  dissolved  in  glycerin,  is 
pumped  into  the  canals.  If  now  provision  for  surgical  rest  of  the 
irritated  pericementum  be  made,  relief  is  tolerably  certain.  A  moldine 
impression  is  taken  of  the  adjoining  tooth,  if  a  bicuspid  or  a  molar,  or 
of  one  the  bicuspids,  if  a  labial  tooth  be  the  one  affected,  and  a  fusible 
metal  die  is  made.  Driven  into  a  block  of  soft  lead,  a  counter-die  is 
formed  and  a  metal  cap  to  cover  the  occlusal  and  part  of  the  buccal  and 
lingual  surface  of  the  tooth  may  be  swaged  in  a  few  moments.  About 
No.  26,  American  gauge,  should  be  the  thickness  of  the  metal.  The 
tooth  is  dried  and  the  cap  attached  by  means  of  zinc  phosphate,  and 
allowed  to  remain  for  a  day  or  two.  This  will  insure  rest  of  the 
affected  pericementum.  If  now  the  gum,  at  a  distance  from  the  tooth, 
be  painted  with  tr.  iodin  and  chloroform  as  a  counter-irritant,  the 
inflammation  usually  subsides  and  almost  disappears  in  a  couple  of 
days.  These  several  measures  are  to  be  regarded  as  the  abortive  treat- 
ment of  alveolar  abscess  ;  they  apply  to  all  cases  if  seen  early  enough, 
and  will  in  the  majority  of  cases  prevent  the  disease  of  the  peri- 
cementum passing  the  early  inflammatory  stages.  In  all  cases  the 
severity  of  the  inflammatory  process  is  lessened  in  proportion  to  the 
thoroughness  with  which  the  antiseptic  measures  are  applied. 


404  SEPTIC  APICAL  PERICEMENTITIS. 

If  the  case  be  a  more  severe  one,  or  at  a  later  stage  than  that 
described,  the  excessive  tenderness  of  the  tooth  may  preclude  any 
attempt  at  drilling  into  the  pulp-chamber  without  the  administration 
of  a  general  anaesthetic.  When  the  cause,  clinical  history,  and  indicated 
therapeutics  in  alveolar  abscess,  are  viewed,  there  can  be  no  two  opinions 
as  to  the  wisdom  of  anaesthetizing  the  patient  and  effecting  an  entrance 
to  the  pulp-canals.  It  cannot  be  too  strongly  emphasized  that  canal- 
sterilization  is  in  order  at  any  stage  of  abscess-formation,  as  is  also  the 
free  and  frequent  use  of  antiseptic  mouth-washes — pyrozone  and  medi- 
trina.  Failing  to  administer  a  general  anaesthetic,  the  canals  are  opened 
as  freely  as  the  tenderness  of  the  tooth  permits ;  the  use  of  any  instru- 
ments, except  broaches  applied  with  the  utmost  delicacy  of  touch,  is 
precluded  by  the  intolerable  pain.  An  effort  is  made  to  limit  the  extent 
of  inflammatory  action.  After  the  early  stages  and  up  to  nearly  the 
point  of  pus-perforation,  hot  applications  in  the  mouth  and  the  use  of 
counter-irritants  to  the  gum  but  provoke  the  inflammatory  condition. 
The  most  effective  measure  is  local  bloodletting  by  means  of  a  leech, 
if  possible,  or  by  making  several  free  cuts  with  a  bistoury,  which  tend 
to  relieve  the  engorged  vessels  of  the  pericementum.  The  mouth  should 
be  washed  with  warm  antiseptics  before  and  after  the  incisions.  Dry 
cups  to  the  back  of  the  neck  and  hot  mustard  foot-baths  are  also  useful 
derivative  measures. 

In  the  still  more  severe  cases  marked  relief  of  the  inflammatory 
symptoms  and  the  pain  follows  the  administration  of  10  gr,  of  Dover's 
powder,  in  addition  to  the  measures  advised.  A  saline  cathartic,  mag- 
nesium sulfate,  should  be  administered  the  next  morning,  with  a  view  to 
relieving  the  constipation  following  the  use  of  the  opium,  and  to  act 
as  a  derivative  by  inducing  free  watery  stools. 

If  high  inflammation  persist  for  more  than  twenty-four  hours,  pus 
is  almost  certainly  present  in  the  pericementum,  and  possibly  more  or 
less  molecular  destruction  of  bone  has  occurred.  In  rare  cases,  where  the 
bone-covering  of  the  root-apex  is  extremely  thin,  the  pus  may  be  at  this 
time  at  the  point  of  exit.  The  dictum  of  surgery,  to  give  vent  to  pus  as 
soon  as  it  is  discovered,  applies  as  well  in  the  condition  under  discussion 
as  anywhere  else.  When  it  is  considered  that  prior  to  evacuation  of  the 
abscess  destruction  of  tissue  is  going  on  in  all  directions,  it  is  evident 
that  tissue-destruction,  complications,  and  the  possibility  of  septic  intox- 
ication, or  even  more  serious  general  disturbances,  will  be  averted  by 
gaining  quick  access  to  the  focus  of  infection  and  removing  it.  Some 
operators  advise  that  an  artificial  opening  be  made  even  in  the  earlier 
stages  of  acute  septic  pericementitis,  recognizing  that  the  case  is  septic 
and  that  radical  relief  is  only  secured  through  complete  antisepsis.  If 
the  case  be  seen  early,  however,  the  abortive  measures  previously  de- 


DISEASES  OF  PERICEMENTUM  EEGINNIXG  AT  THE  APEX.     405 

scribed  can  be  instituted.  The  old  practice  of  waiting  until  the  pus  has 
penetrated  the  alveolar  periosteum  is  unsurgical. 

To  insure  quiet  of  the  patient  while  opening  into  the  apical  space 
from  the  gum,  it  is  advisable  to  administer  nitrous  oxid,  if  this  agent 
be  available.  The  mouth  should  be  freely  washed  with  strong  anti- 
septics and  a  cut  made  through  the  gum  over  the  apex  of  the  aifected 
root.  The  incision  is  permitted  to  bleed,  and  is  then  packed  with 
cotton  containing  phenol  sodique.  As  soon  as  bleeding  has  ceased 
the  nitrous  oxid  is  administered  ;  if  it  be  not  at  hand,  a  pellet  of  cotton 
containing  a  10  per  cent,  solution  of  cocain  is  laid  against  the  periosteum. 
The  first  cut,  made  with  a  stout-pointed  bistoury,  penetrates  to  the  bone. 
A  sharp  scaler  or  chisel  is  used  to  scrape  away  a  small  area  of  the 
alveolar  periosteum ;  next  a  spear-pointed  drill,  revolving  rapidly,  is 
quickly  passed  through  the  outer  alveolar  plate  into  the  apical  space. 
The  apices  of  the  roots  lie,  as  a  rule,  slightly  higher  than  the  line 
of  mucous  membrane  reflection.  The  cut  should  be  free  and  the  peri- 
osteum scraped  away,  to  avoid  annoying  and  disfiguring  emphysema  of 
the  cheek-tissues,  which  may  occur  if  these  precautions  be  not  taken. 
The  pain  following  the  operation  may  be  relieved,  after  bleeding  has 
ceased  and  the  cavity  has  been  washed  out  with  warm  antiseptics,  by 
pushing  a  crystal  of  cocain  hydrochlorid  into  the  cavity  as  far  as  it  will 
go.  As  soon  as  the  inflammatory  symptoms  have  subsided  sufficiently 
to  permit  working  upon  the  tooth,  the  pulp-canals  are  to  be  opened  and 
sterilized. 

The  case  may  not  be  seen  until  its  third  stage,  when  the  pus  is  in 
the  tissues  exterior  to  the  alveolar  process.  In  these  cases  a  very  sharp 
bistoury  is  passed  into  the  swelling  at  its  most  prominent  part  and  a  deep 
and  free  incision  made.  In  case  the  inflammation  have  extended  to  the 
tissues  of  the  cheek,  an  outcome  most  to  be  feared  in  abscess  upon  the 
lower  third  molar  or  upon  the  upper  first  or  second  molar,  antiphlo- 
gistics  should,  be  applied  to  the  cheek — 


Plumbi  acetat., 

3j; 

Tr.  opii, 
Aqu£e, 

5j; 
Oj.- 

-M, 

Compresses  wet  with  this  preparation  are  laid  upon  the  cheek,  and  a 
free,  deep  incision  made  in  the  gum  at  the  junction  with  the  cheek. 
An  examination  should  always  be  made  of  the  palatal  and  lingual  alve- 
olar aspects,  to  note  whether  the  inflammatory  and  suppurative  process 
tends  to  take  either  of  those  directions. 

If,  in  connection  with  the  lower  third  molar,  marked  swelling  is  ob- 
served in  the  submaxillary  triangle,  free  incision  of  the  tissues  of  the 


o». 


406  SEPTIC  APICAL  PERICEMENTITIS. 

floor  of  the  mouth  should  be  made  at  the  angle  of  junction  with  the 
bone.  The  cut  should  be  made  close  to  the  bone  and  into  it,  but  not 
too  deep,  lest  the  mylohyoid  artery  or  nerve  be  injured.  In  all  cases 
which  threaten  to  open  externally  the  antiphlogistic  compresses  are  to 
be  continuously  applied  externally,  and  after  incision  stimulant  mouth- 
washes should  be  used  ;  that  recommended  by  Prof.  Garretson  is  excel- 
lent— tr.  myrrhse  et  capsici  in  water. 

It  is  ever  to  be  borne  in  mind  that  so  long  as  the  source  of  infection 
remains  pus-formation  continues,  and  so  long  as  pus  forms,  tissue-de- 
struction is  in  progress ;  furthermore,  in  proportion  to  the  amount  of 
tissue-loss  perfect  recovery  after  alveolar  abscess  is  delayed  or  imperfect. 

While  it  is  the  clinical  experience  of  nearly  every  operator  that  a 
tooth  and  adjacent  structures  may  recover  from  inflammation  which 
involves  not  only  the  first  tooth  attacked,  but  by  an  extension  of  the 
inflammatory  process  involves  the  general  periosteum  and  neighboring 
teeth,  provided  the  case  receive  prompt  and  decisive  surgical  treatment, 
yet  the  danger  of  septicaemia  in  prolonged  cases  is  always  imminent. 
When  the  general  periosteum  is  involved,  as  shown  by  extensive  boggy 
swelling  in  the  mouth,  if  several  free  incisions  carried  to  the  bone  do 
not  aflbrd  prompt  relief,  the  tooth  which  is  the  centre  of  infection  should 
be  promptly  extracted.  If;  in  the  course  of  the  pericementitis,  chills, 
followed  by  fever,  a  coated  tongue,  and  much  physical  depression  occur, 
a  general  infection  is  to  be  feared,  and  no  time  should  be  lost  in  steriliz- 
ing the  mouth,  extracting  the  tooth,  and  subjecting  the  socket  to  free 
spraying  with  antiseptics. 


CHAPTER   XXII. 
SEPTIC  APICAL  PERICEMENTITIS  (CHRONIC). 

Chronic  septic  apical  pericementitis  exhibits  several  grades  as  to 
its  extent  and  effects ;  one  of  the  more  pronounced  types  or  grades 
being  the  direct  outcome  of  acute  apical  pericementitis,  resulting  in  pus- 
formation,  a  condition  known  as  chronic  alveolar  abscess.  After  the 
discharge  of  pus,  either  spontaneously  or  through  surgical  aid,  as  noted 
in  the  discussion  of  acute  alveolo-dental  abscess,  the  source  of  infection 
remains,  and  pus-formation  continues  as  a  chronic  process,  which  rarely 
disappears  spontaneously  ;  the  acute  inflammatory  symptoms,  however, 
subside  and  do  not  reappear  unless  there  is  some  interference  with  the 
escape  of  the  pus. 

Clinically  chronic  abscess  presents  itself  in  two  classes  :  cases  with- 
out a  fistula  communicating  with  the  mouth-cavity  or  other  part,  and 
those  in  which  the  pus  finds  vent  through  a  fistula. 

Chronic  Alveolo-dental  Abscess  withouj  Fistula. 

Pathology  and  Morbid  Anatomy. — Although  the  acute  inflamma- 
tory symptoms  may  subside  and  be  replaced  by  those  of  atonic  hyper- 
semia,  as  soon  as  pus  finds  vent  through  the  canal  of  the  tooth ; 
pus-formation — /.  e.,  tissue-destruction — proceeds  radially  from  the 
affected  root.  The  conditions  existing  immediately  after  evacuation 
of  the  pus  are  a  denuded  root-apex,  about  which  are  peptonized 
(liquefied)  effusions,  in  which  are  shreds  of  dead  tissue,  and  dead,  dying, 
and  disintegrated  inflammatory  corpuscles,  occupying  a  cavity  bounded 
by  embryonic  tissue,  which  is  being  gradually  invaded  by  pyogenic 
organisms ;  the  surrounding  tissue  is  being  transformed  into  or  replaced 
by  embryonic  tissue,  the  result  of  inflammatory  degeneration.  The  cavity 
bounded  by  this  w^all  of  embryonic  tissue  is  constantly  increasing  in 
size.  In  long-continued  cases  organization  of  the  boundary-wall  may 
occur,  and  the  cavity  be  enclosed  by  a  capsule  of  vascular  fibrous  con- 
nective tissue.  If  teeth  be  extracted  at  this  stage,  this  fibrous  sac  may 
come  away  with  the  tooth  ;  it  is  the  structure  sometimes  termed  a  pyo- 
genic membrane. 

The   influence  of    gravity  has  much  to  do  with  the  direction  of 

407 


408 


SEPTIC  APICAL  PERICEMENTITIS. 


tissue-destruction  in  chronic  abscess  (Figs.  314  and  315).     In  the  lower 
jaw  the  tendency  is  to  burrow  into  the  cancellated  tissue  of  the  bone 


Fig.  314. 


Fig.  316. 


Fig.  314.— Chronic  blind  abscess  of  upper  incisor,  showing  tendency  of  pus  to  progressively  destroy 
pericementum  owing  to  the  influence  of  gravity. 

Fig.  315.— Chronic  blind  abscess  upon  lower  tooth,  showing  tendency  of  pus  to  sink  into  the  sub- 
stance of  the  lower  maxilla,  owing  to  the  influence  of  gravity. 

away  from  the  tooth,  so  that  destruction  of  the  pericementum  may  not 
be  very  extensive.     In  the  upper  jaw  the  tendency  is  to  spread  along 

the  pericementum  and  into  the  cancellated 
bone,  so  that  the  cavities  of  chronic  abscess 
upon  the  upper  anterior  teeth  particularly  may 
cause  extensive  excavation  in  the  palatal  pro- 
cess of  the  superior  maxillary  bone  (Fig.  316). 
The  pus  may  burrow  in  irregular  and  circuitous 
directions,  until  it  finds  external  vent.  In  long- 
established  cases  the  denuded  root-apex  becomes 
the  seat  of  calcic  deposits. 

Symptoms  and  Diagnosis. — Attention  is 
directed  to  some  pulpless  tooth  or  to  a  crownless 
root,  around  which  the  gum-color  is  deepened  and  which  is  more  or  less 
loose,  indicating  softening  of  its  pericementum,  but  no  fistula  is  present. 
After  isolation  under  rubber-dam  pus  may  or  may  not  be  discoverable 
in  the  canals.  If  pus  is  seen,  the  diagnosis  is  evident.  If  pus  be  not 
seen,  and  the  canals  be  drenched  with  a  50  per  cent,  solution  of  sodium 
dioxid,  the  application  being  continued  until  it  is  reasonably  certain  that 
all  infective  material  in  the  canals  has  been  destroyed,  the  canals  may 
be  closed  with  the  dressing  usual  in  such  cases,  twists  of  cotton  sat- 
urated with  an  antiseptic  oil,  when  irritation  should  be  allayed  if  an 


CHRONIC  ALVEOLO-DENTAL  ABSCESS   WITHOUT  FISTULA.  409 

abscess  does  not  exist ;  but  if,  after  some  hours,  or  a  day  or  two,  in- 
flammatory symptoms  arise,  the  presence  of  pus  should  be  suspected, 
and  its  existence  may  be  confirmed  by  its  flow  upon  removing  the 
<;anal-dressing.  More  or  less  pus  should  always  be  suspected  about  the 
roots  of  teeth  which  are  crownless  or  pulpless,  and  have  unfilled  canals, 
when  the  tooth  is  loose,  and  the  overlying  gum  injected.  In  doubtful 
<3ases  canal-fillings,  even  after  thorough  cleansing  with  sodium  dioxid, 
are  made  of  an  easily  removable  material,  and  are  only  made  tentatively 
until  it  is  certain  that  a  tightening  of  the  pericementum  and  a  fading  of 
the  deepened  gum-color,  instead  of  an  increased  irritation,  follow  their 
insertion. 

Prognosis. — The  fate  of  the  aifected  root  depends  upon  the  amount 
of  tissue-destruction,  the  length  of  time  suppuration  has  been  going  on, 
and  the  recuperative  powers  of  the  patient's  tissues,  together  "vvith — 
most  important  of  all — the  thoroughness  with  which  infection  and  the 
sources  of  infection  are  removed.  If  the  last-named  object  can  be  at- 
tained, astonishing  recoveries  occur;  in  its  absence,  the  tooth  is  certain  to 
be  permanently  crippled  and  to  be  a  menace  to  the  surrounding  tis- 
sues. It  is  remarkable,  however,  how  long  pus-formation  may  con- 
tinue about  the  root  of  a  tooth,  and  cause  comparatively  little  disturb- 
ance, except  in  a  very  circumscribed  field.  The  presence  of  pus  in 
any  cavity  of  the  body  should  never  be  regarded  as  without  danger ; 
and,  doubtless,  constitutional  eifects  from  pus-formation  about  the 
teeth  are  often  present  without  the  operator  being  cognizant  of 
them. 

Treatment. — The  principle  of  treatment  is  to  remove  all  pus,  dead 
tissue,  and  infective  organisms,  induce  a  regeneration  of  tissue  to  obliter- 
ate the  abscess-cavity,  and  prevent  future  infection.  The  heroic  and 
most  successful  method  of  treatment  is  to  remove,  as  a  primary  meas- 
ure, the  mechanical  impediment  to  the  thorough  washing  and  sterilizing 
of  the  abscess-cavity.  So  long  as  the  entrance  to  the  abscess-cavity  and 
the  exit  from  it  are  but  the  constricted  passage  of  a  root-canal,  it  is 
evident  that  the  complete  filling  and  emptying  of  the  abscess-cavity  w411 
be  attended  with  difficulty,  depending  upon  the  size  of  the  canal  and 
of  the  abscess-cavity.  If,  however,  an  external  fistula  exist,  the  com- 
plete washing  of  the  tract  and  emptying  of  the  cavity  are  muc-h  fiicilitated  ; 
abscess  with  external  fistula  is  much  more  amenable  to  treatment  than 
when  no  such  exit  exists.  The  tendency  of  modern  practice,  there- 
fore, is  to  establish  a  free  artificial  fistula  in  all  cases  of  so-called  blind 
abscess. 

The  canals  are  cleansed  with  sodium  dioxid  solution,  and  the  canal 
length  and  direction  recorded  upon  a  broach.  This  length  is  measured 
upon  the  gum  to  determine  the  point  of  entrance.     The  most  certain 


410 


SEPTIC  APICAL  PERICEMENTITIS. 


4    6    5 

Tubular  knives. 


1       2 

Walker-Younger  trephines. 


and  quickest  method  of  making  the  proper  entrance  is  to  administer 

nitrous  oxid,  or,  if  that  be    not 
Fig.  317.  Fig.  318.  available,  to  inject   a  few  drops 

of  a  boiled  solution  (10  per  cent.) 
of  eucain  into  the  gum  and  re- 
move a  cylindrical  portion  of 
gum-tissue  by  means  of  a  Rollin's 
tubular  knife,  or  make  an  incision 
to  the  bone  and  scrape  off  a  por- 
tion of  periosteum  ;  entrance  to 
the  abscess-cavity  may  then  be 
made  by  means  of  a  drill  or  small 
trephine  (Fig.  318).  The  case  is 
now  treated  as  one  of  abscess  with 
fistula  (which  see). 

Cases  may  be  treated  without 
making  an  artificial  fistula,  but  the  results  are  rarely  so  satisfactory  and 
the  cure  seldom  so  complete  as  when  an  artificial  opening  is  made.  The 
best  results  are  obtained  where  the  destruction  of  tissue  has  been  very 
limited,  where  the  pus  has  found  exit  through  the  canal  at  an  early 
period,  and  where  the  case  is  seen  soon  after  subsidence  of  the  active 
inflammation. 

The  tooth-cavity  is  cleansed  mechanically,  syringing  freely  with 
meditrina  or  3  per  cent,  pyrozone  solution,  and  the  rubber-dam  adjusted. 
The  canals  are  cleansed  by  repeated  applications  of  sodium  dioxid  solu- 
tion, continued  until  the  apex  of  the  root  is  passed,  when  the  canals  are 
forcibly  syringed  with  an  acid  solution  of  hydrogen  dioxid  until  effer- 
vescence ceases.  The  canal  is  now  thoroughly  dried  and  filled  with  an 
antiseptic ;  Black's  1-2-3  mixture,  campho-ph^nique,  oil  of  cassia,  and 
thymol  are  all  useful.  If  the  canals  have  been  well  cleansed  and  the 
antiseptics  employed  have  been  carried  into  the  abscess-cavity,  further 
use  of  antiseptics  is  not  absolutely  necessary,  but  it  is  prudent  to  use 
them  to  complete  a  possibly  partial  sterilization.  The  antiseptic  may 
be  driven  in  spray  into  all  portions  of  the  abscess-cavity,  by  blowing  a 
blast  of  air  into  the  canal  through  a  chip-blower.  The  canals  are  next 
partially  dried  and  loosely  filled  with  cotton,  and  the  crown-cavity 
hermetically  sealed. 

If  in  the  course  of  two  or  three  days,  the  tooth  appears  tighter  and 
the  vascular  symptoms  in  the  gum  subside,  a  cure  may  be  anticipated. 
As  a  precautionary  measure,  the  tooth  may  be  placed  under  rubber-dam, 
the  seal  and  canal-filling  removed,  and  the  condition  as  regards  odor  and 
the  presence  of  pus  or  blood-stains  noted.  If  odor  be  present,  a  second 
cleansing  with  sodium  dioxid  should  be  practised  as  before,  the  canals 


CHRONIC  ALVEOLO-DENTAL  ABSCESS  WITH  FISTULA.        411 

dried,  and  a  cotton  twist  saturated  with  thymol  packed  into  them.  If 
no  symptoms  arise,  this  dressing  may  remain  a  week  or  hmgcr.  At  the 
expiration  of  this  time  the  abscess-cavity  is  probably  filled  with  organ- 
izing granulation-tissue.  The  canal  may  be  opened  under  extraordinary 
antiseptic  precautions  and  filled  with  melted  paraffin  and  aristol, 
nosophen,  euthymol,  or  iodoform.  The  crown-cavity  may  be  filled  with 
zinc  phosphate,  and  the  case  be  dismissed  for  six  months  or  longer.  If  a 
gold  filling  is  indicated,  this  time  should  elapse  before  it  is  inserted. 

If  the  tooth  rebels  against  closing  after  more  than  one  cleansing  with 
sodium  dioxid,  it  is  scarcely  worth  while  temporizing — an  artificial 
fistula  should  be  established. 

In  rare  instances  a  cure  of  even  extensive  suppuration,  with  large 
cavity,  may  be  effected  without  an  artificial  fistula,  by  sterilizing  the 
affected  root,  aspirating  the  pus,  washing  out  the  abscess-cavity,  and 
inducing  regeneration.  The  tooth  should  be  isolated,  its  canals  cleansed 
with  sodium  dioxid  and  washed.  As  deep  into  the  canal  as  possible  the 
nozzle  of  a  large  syringe  is  placed ;  temporary  stopping  is  packed  into 
the  crown-cavity  tightly  about  the  syringe  ;  the  piston  is  withdrawn, 
drawing  the  pus  into  the  syringe.  The  withdrawal  may  fiiil  entirely 
owing  to  the  apical  foramen  being  blocked  by  shreds  of  dead  tissue. 
If  the  attempt  be  successful,  the  stopping  is  removed,  the  canals  dried, 
and  a  drop  or  two  of  a  25  per  cent,  solution  of  pyrozone  pumped  into 
the  abscess-cavity,  more  being  added  until  eifervescence  ceases.  When 
the  canals  are  dried  they  are  filled  with  an  antiseptic — thymol,  campho- 
phenique,  etc. — driven  in  spray  into  the  abscess-cavity  by  blasts  of  warm 
air.  If  the  evidences  of  disturbance  subside,  the  case  is  treated  as  in 
the  former  instance.  If  the  tooth  rebel  against  closiilg,  an  artificial 
fistula  should  be  established. 

Chronic  Alveolo-dental.  Abscess  with  Fistula. 

Morbid  Anatomy  and  Pathology, — The  conditions  found  attend- 
ant upon  this  disease  depend,  first,  upon  the  length  of  time  elapsing 
between  the  inception  of  the  inflammatory  process  and  the  evacuation 
of  the  abscess  ;  secondly,  upon  the  surgical  anatomy  of  the  parts ;  and, 
thirdly,  upon  the  physical  condition  of  the  patient.  In  the  majority  of 
cases  the  pus  from  acute  abscess  finds  exit  almost  immediately  over 
the  apex  of  the  affected  root,  in  the  course  of  a  few  days,  so  that  at 
this  time  a  canal  lined  with  embryonic  connective  tissue  may  connect 
with  a  cavity  of  any  size  lined  with  embryonic  tissue,  the  walls  of  -which 
continue  in  a  state  of  infection.  If  the  process  continue,  organization 
of  the  abscess-wall  occurs  as  in  abscess  without  fistula. 

Instead  of  finding  exit  by  a  direct  path  to  the  exterior,  the  pus  may 
burrow"  along  the  length  of  the  pericementum  and  discharge  at  the  neck 


412 


SEPTIC  APICAL  PERICEMENTITIS. 


of  the  tooth.  One-half  or  more  of  the  lateral  aspect  of  the  pericemen- 
tum may  remain  vital,  although  involved  in  a  chronic  inflammation, 
the  remainder  being  destroyed.  Where  the  apices  of  the  roots  of  upper 
posterior  teeth  lie  in  very  close  proximity  to  the  floor  of  the  antrum, 
perforation  of  this  floor  may  occur  before  tissue-destruction  has  pro- 
ceeded far  enough  in  other  directions  to  afibrd  escape  to  the  pus.  Ex- 
tensive pus-accumulations  may  occur  in  the  antrum  in  consequence. 
Other  paths  of  pus-exit  are  noted  in  Chapter  XXI.,  in  connection  with 
acute  abscess  ;  at  such  points  the  discharge  may  remain  persistent.  In 
some  cases,  after  the  subsidence  of  the  acute  inflammatory  symptoms, 
pus-discharge  may  lessen  and  finally  cease,  the  fistula  healing,  although 
pus-formation  in  the  substance  of  the  bone  continues.  The  discharge 
only  ceases,  however,  when  the  pus  finds  some  other  point  of  discharge  ; 
usually  this  is  through  the  canal  of  the  affected  tooth ;  the  condition 
then  becomes  one  of  blind  abscess.  The  burrowing  of  the  pus  continues, 
however,  and  at  a  late  period  may  find  exit  at  a  distant  point.  Upon 
a  lower  tooth,  particularly  the  incisors,  the  pus  may  burrow  downward 
through  the  cancellated  tissue  of  the  bone  and  emerge  at  the  base  of  the 
bone  and  open  upon  the  face  (Figs.  319  and  320). 

In  other  cases  the  pus  may  perforate  the  bone,  and  find  passage  along 
the  submuscular  tissue  of  the  depressor  muscles  of  the  lip,  opening 
-p^^  g^g  above  or  under  the  point  of  the  chin.     The 

apices  of  the  roots  of  teeth  lying  beneath  the 
line  of  insertion  of  the  mylohyoid  muscle 
may  cause  an  abscess  to  open  in  the  neck- 
cavity.  Cryer  records  a  case  where  an  ab- 
scess opening  upon  the  face  immediately 
anterior  to  the  line  of  the  facial  artery, 
was   traced  to  the  root  of  a  lower  molar; 

Fig.  320. 


Fig.  319.— Chronic  alveolar  abscess  of  the  root  of  a  lower  incisor,  with  abscess-cavity  passing  through 
the  body  of  the  bone  and  discharging  on  the  skin  beneath  the  chin  :  a,  very  large  abscess- 
cavity  ;  6,  mouth  of  the  ilstula.    (Black.) 

Fig.  320.— Fistula  passing  down  through  the  body  of  the  lower  maxilla.    (Black.) 


CHRONIC  ALVEOLO-BENTAL  ABSCESS   WITH  FISTULA.        413 


Fig.  321. 


the  direction  of  the  siuiis  is  .shown   in  Fig.  322.     In  a  case  having  a 

similar  anatomical  association,  the  pus 
penetrated  the  bone  lingually,  was  en- 
capsuled  beneath  the  internal  ])tervgoid 
muscle,  and  appeared  as  a  swelling  at 
the  inner  aspect  of  the  angle  of  the  jaw. 
Occasionally  the  apices  of  the  roots  of 
lower  molars  are  separated  from  the 
inferior  dental  canal  by  only  a  thin  lam- 
ina of  bone,  so  that  discharge  into  this 

Fig.  :V22. 


Fig.  321.— Chronic  alveolar  abscess  at  the  root  of  a  lower  incisor,  with  a  fistula  discharging  on  the 
face  under  the  chin :  a,  abscess-cavity  in  the  bone ;  b,  b.  b,  fistula  following  in  the  periosteum 
down  to  the  lower  margin  of  the  body  of  the  bone  and  discharging  on  the  skin.    (Blacli.) 

Fig.  322.— Abscess  with  tortuous  sinus,  opening  upon  the  face  :  ,4,  tissue  of  cheek  :  B,  floor  of  mouth  ; 
C,  abscess-tract. 

canal  may  occur  with  infiltration  along  the  vessels  and  nerves  in  the 
canal.  While  discharge  into  the  nasal  chamber  is  most  frequently  asso- 
ciated with  abscess  upon  the  central  incisors,  abscess  upon  molars  may 
discharge  into  the  same  cavity. 

Symptoms  and  Diagnosis. — The  symptoms  of  the  condition  are  a 
fistulous  opening  in  the  gum  or  some  other  part,  in  proximity  to  or  con- 
nected with  a  pulpless  tooth.  The  tooth  may  have  an  open  cavity,  con- 
tain a  filling,  bear  an  artificial  crown,  or  be*  free  from  caries.  In  other 
cases,  the  root  which  is  the  centre  of  infection  may  lie  buried  in  the  gum 
and  be  invisible.  The  source  of  the  trouble  in  rare  cases  may  be  an 
impacted  tooth  (see  Chapter  X.).  As  a  rule,  the  seat  of  the  affection  is 
indicated  by  sluggish  vascular  disturbance  in  the  gum  overlying  the 
offending  root.  Any  fistula  existing  in  the  maxillary  region,  either 
within  or  without  the  mouth,  should  be  suspected  to  have  originated 
in  a  septic  pericementitis  of  some  tooth.  A  soft  silver  probe  shotdd  be 
pas.sed  along  the  tract  to  determine  its  direction,  and,  if  possible,  which 
tooth  is  affected.  As  a  rule,  such  a  tooth  exhibits  objective  evidences 
of  abscess,  and  the  patient  will  give  a  history  of  subjective  symptoms 
— those    of  inflammation    of   pericementum.      If  the    tooth    indicated 


414  SEPTIC  APICAL  PERICEMENTITIS. 

as  the  affected  one  be  free  from  caries,  the  thermal  test  should  be 
applied  to  determine  the  degree  of  vitality  of  the  pulp.  Should  the 
tooth  not  respond  to  applications  of  cold,  it  is  possible  it  may  offer 
slight  response  to  applications  of  heat.  It  is  next  examined  by 
light  reflected  from  the  ordinary,  or,  better,  the  electric  mouth- 
mirror,  when,  if  the  pulp  be  dead,  opacity  of  the  crown  will  be 
detected.  An  abscess  upon  an  upper  incisor  opening  upon  the  nasal 
floor  may  cause  a  discharge  simulating  that  of  ozsena.  An  examination 
of  the  nose  will  reveal  a  teat-like  elevation  upon  the  mucous  membrane 
covering  the  nasal  floor  and  an  incisor  beneath  will  be  found  carious 
and  having  a  putrescent  pulp,  or,  if  non-carious,  there  will  be  a  history 
of  traumatic  pericementitis  and  upon  inspection  an  opacity.  It  may  be 
mentioned  here,  in  connection  with  death  of  the  pulp  from  trauma- 
tism, that  continuous  thread-biting,  and  biting  very  hard  substances, 
such  as  pieces  of  ice,  nuts,  etc.,  may  cause  death  of  the  organ,  pre- 
sumably by  thrombosis. 

It  is  possible  that  the  direction  taken  by  a  probe  passed  into  the 
fistula  will  point  away  from  the  teeth  present,  passing  into  a  space  from 
which  a  tooth  has  been  extracted.  In  that  event  the  presence  of  a  root- 
fragment,  or  piece  of  necrosed  process,  may  be  suspected.^  If  the 
neighboring  teeth  be  excluded  as  causes  of  the  inflammation,  there 
should  be  no  hesitation  in  making  an  exploratory  incision  down  to  the 
end  of  the  probe  which  has  been  passed  into  the  fistula ;  cases  of  den- 
tigerous  cysts  have  been  detected  in  this  manner.  This  condition,  how- 
ever, should  be  suspected  when  there  is  an  absence  of  a  tooth  or  teeth 
from  the  arch,  no  evidence,  past  or  present,  of  pericementitis  in  any  of 
the  teeth  of  the  arch,  and  a  cystic  tumor  present  in  the  jaw,  or  a  fistula 
discharging  upon  the  face  after  a  history  of  maxillary  periostitis. 
Caries  or  necrosis,  although  in  many  cases  the  result  of  septic  apical 
pericementitis,  may  exhibit  fistulse  opening  into  the  mouth,  without 
evident  connection  with  the  teeth.  As  a  rule,  cases  of  necrosis  exhibit 
marked  evidences  of  chronic  inflammation  of  the  tissues  overlying  the 
dead  or  dying  bone  ;  there  are  usually  several  fistulse  discharging  from 
it.  Caries  may  present  but  a  single  fistula  and  closely  simulate  ordinary 
alveolar  abscess.  Diagnosis  is  made  by  passing  an  excavator  through 
the  fistula.  Dead  bone  is  readily  detected  by  touch  ;  it  has  a  rotten 
feel.  In  caries  the  instrument  may  be  passed  through  the  dead  bone  in 
various  directions,  and  a  characteristic  sound  be  elicited  by  tapping 
upon  it.  Careful  examination  of  the  teeth  must  be  made  in  all  of  these 
cases  to  determine  the  condition  of  the  pulps  and  pulp-canals.  In  pass- 
ing an  instrument  through  a  fistula  to  the  apex  of  a  tooth-root, 
where  the  disease-process  has  been  of  long  duration,  it  may  be  found 
^  See  case  of  Black's,  American  System  of  Dentistry,  vol.  i. 


CHRONIC  ALVEOLO-DENTAL  ABSCESS   WITH  FISTULA.        415 

that  the  a})ex  of  the  root  is  denuded  of  pericementum  and  roughened ; 
that  is,  the  apical  eementutn  is  necrotic ;  foreign  deposits  may  be 
detected  occupying  portions  of  the  necrotic  area. 

Treatment. — The  first  step  of  treatment  is  the  thorough  eradication 
of  the  source  of  infection.  The  tooth,  filled  or  unfilled,  bearing  arti- 
ficial crown,  or  no  matter  what  its  condition,  should  have  its  root-canals 
freely  opened  to  their  apices.  The  presence  of  a  canal-filling  should 
not  hinder  the  complete  opening,  as  the  canal  may  appear  to  be  filled, 
and  in  reality  be  imperfectly  filled.  If  the  abscess  be  upon  a  root 
which  cannot  be  utilized  by  crowning,  the  root  should  be  at  once 
extracted.  Impacted  teeth  should  be  removed  by  surgical  operation. 
If  the  centre  of  suppuration  be  dead  bone,  it  should  be  removed  by 
like  means. 

In  cases  where  there  are  useful  tooth-roots,  the  tooth  should  be 
isolated  under  rubber-dam,  and  saturated  sodium  dioxid  solutions  be 
pumped  into  the  canals  until  it  is  certain  they  are  cleansed  and  steril- 
ized. Fine  canal-cleansers  are  then  passed  through  the  apex  of  the 
affected  root,  opening  into  the  abscess-cavity.  The  canal  and  cavity 
are  now  freely  syringed  with  3  per  cent,  pyrozone  until  the  contents  of 
the  abscess-cavitv  are  driven  bubbliup;  through  the  fistula.  This  forcible 
irrigation  is  continued  until  the  fluid  comes  away  clear  and  without 
bubbling.  M.  L.  Rhein  ^  advises  that  a  solution  of  mercuric  chlorid 
in  hydrogen  dioxid  be  used  for  this  washing.  The  wall  of  embrvonic 
tissue  lining  the  abscess-cavity  being  frequently  infected  with  organisms 
which  the  hydrogen  dioxid  alone  fails  to  kill,  mercuric  chlorid  is  added 
to  destroy  them.  The  same  writer^  advises  that  a  positive  electrode,  a 
fine  wire  of  chemically  pure  zinc,  be  inserted  to  the  bottom  of  the  canal 
and  the  current  from  a  cataphoresis  apparatus  applied.  By  electrolysis, 
zinc  oxychlorid  is  formed  at  the  positive  pole  by  the  action  of  chlorin 
and  oxygen,  liberated  from  the  fluids  of  the  part,  acting  upon  the  zinc  ; 
the  zinc  oxychlorid  in  its  nascent  state  is  forced  cataphorically  into 
the  walls  of  the  abscess,  where  it  acts  as  an  efl^ective  antiseptic  and 
induces  the  formation  of  granulation-tissue  ;  hence  the  regeneration  of 
tissue. 

The  usual  practice  is  to  fill  the  root-canal  with  some  ]iowerful  anti- 
septic, such  as  campho-phenique,  the  1-2-3  mixture  of  Black,  or  one 
of  the  antiseptic  oils,  and,  by  pumping  witlf  a  smooth  broach,  force  the 
antiseptic  through  the  abscess-cavity  and  fistula.  Fluids  maybe  induced 
to  flow  an  astonishing  distance  if  the  pumping  be  persisted  in.  They 
will  make  their  way  along  such  tracts  as  shown  in  Figs.  319,  321, 
and  322. 

Their  flow  may  be  induced  in  some  cases  by  dipping  a  sterilized 

1  Items  of  Interest,  1897.  ''  Ibid. 


416 


SEPTIC  APICAL  PERICEMENTITIS. 


323. 


rubber  cleaning-cap  (Fig.  323)  in  mercuric-chlorid  solution  and  pressing 
it  firmly  upon  the  gum  over  the  fistula,  then  relaxing  the  pressure  until 
the  cap  rises  and  draws  the  antiseptic  in  the  canal, 
along  the  abscess-tract. 

The  canal  is  dried  and  filled  with  the  paraffin- 
aristol  mixture,  or  with  thread  dipped  in  an  anti- 
septic oil,  and  the  crown-cavity  hermetically  scaled. 
Nature  should  now  complete  the  cure  by  obliterating 
the  abscess-cavity  with  embryonic  tissue,  which  sub- 
sequently organizes.  In  twenty-four  hours  but  a 
slight  serous  flow  should  be  noted,  the  patient  having 
been  directed  to  use  antiseptic  mouth-washes  freely. 
In  about  three  days  no  exudation  should  be  present, 
and  in  a  week  the  fistula  should  be  healed.  Unless  a 
pus-discharge  be  observed,  the  tooth  should  remain 
sealed  for  a  week,  or,  better,  two  weeks,  and  if  filled 
with  paraffin  may  remain  permanently  sealed.  If  pus-discharge  appear, 
the  tooth  should  be  opened  and  treated  as  before. 

If  the  case  be  one  where  an  artificial  fistula  has  been  established,  the 
wound  should  be  kept  from  healing,  after  the  antiseptic  washing,  by 
packing  it  daily  with  nosophen-gauze. 

If  a  serous  discharge  persist  longer  than  a  week,  a  root-apex 
denuded  of  pericementum,  saturated  with  noxious  material,  and  prob- 
ably encrusted  with  deposits  of  calculi,  may  be 
suspected  (Fig.  324).  A  sterilized  excavator 
should  then  be  passed  into  the  fistula  and  over 
the  apex  of  the  root,  to  discover  the  amount  of 
denudation  and  the  presence  of  deposits.  If 
deposits  be  discovered,  the  root  should  be  solidly 
filled;  and  nosophen-gauze  ba  forced  into  the 
abscess-cavity,  distending  the  fistula  ;  if  the  latter 
be  small,  it  may  be  enlarged  by  an  incision  and 
then  packed.  As  soon  as  free  exposure  of  the 
root  is  obtained  a  fissure-bur  may  be  used  to  cut 
off  the  portion  of  root  projecting  into  the  abscess- 
cavity  ;  the  cut  edges  of  the  root  may  be  rounded  by  means  of  scalers. 
It  is  a  serviceable  measure  to  scrape  the  abscess-walls  in  these  cases, 
removing  the  debilitated  and  degenerating  tissue  and  inducing  healthy 
granulation.  The  cavity  is  packed  with  cotton  and  phenol  sodique 
until  bleeding  ceases,  and  a  packing  of  nosophen-gauze  is  inserted,  to  be 
renewed  in  daily  lessening  amount  until  the  abscess-cavity  is  filled  with 
granulations.  The  patient  should  use  freely  antiseptic  mouth-washes. 
Each  fresh  packing  should  be  preceded  by  an  antiseptic  douche. 


Fig.  324. 


Chronic  abscess,  showing 
denudation  of  apex  of 
root  (a  to  h),  with  de- 
posits of  calculi  (a)  upon 
cementum. 


CHRONIC  ALVEOLO-DEXTAL  ABSCESS   WITH  FISTULA. 


417 


Fig.  325. 


In  some  cases  of  anomalous  root-form,  such  as  a  sharp  bend  upon 
the  upper  end  of  the  root,  which  renders  it  imj)ossil)lc  to  gain  access  to 
the  apex  of  the  root  even  with  the  aid  of  sulfuric  acid,  it  may  be  neces- 
sary to  treat  the  abscess  through  the  fistulous  opening.  The  roots 
should  be  sterilized  and  cleansed  to  as  great  a  depth  as  possible  with 
the  aid  of  sulfuric  acid  and  fine  cleansers,  and  an  endeavor  made  to 
force  hydrogen  dioxid  through  the  apical  foramen  and 
out  of  the  fistula  by  means  of  a  syringe.  The  cavity 
of  the  crown  should  be  filled  with  pink  gutta-percha, 
and  through  it  the  nozzle  of  a  syringe  filled  with  3  per 
cent,  pyrozone  thrust  well  up  the  canal.  When  the 
piston  of  the  syringe  is  forced  down,  the  solution  may 
appear  at  the  opening  of  the  fistula,  or  it  may  fail  to 
penetrate  the  foramen,  and  the  backward  pressure  may 
force  the  gutta-percha  from  position.  In  that  event 
myrtol  should  be  placed  in  the  canal,  which  should  be 
filled  with  thread  holding  the  same  material.  Three  per 
cent,  pyrozone  should  then  be  injected  into  the  abscess- 
cavity  through  the  fistula  until  eifervescence  ceases. 
The  nozzle  of  a  minim  syringe  (Fig.  325),  charged  with 
campho-phenique,  or  the  1-2-3  mixture,  is  then  passed 
into  the  abscess-sac,  and  a  couple  of  drops  deposited. 
In  very  many  cases  the  abscess  will  then  proceed  to 
recovery.  The  treatment  should  be  repeated,  if  neces- 
sary. If  several  dressings  applied  at  intervals  of  a 
week  do  not  cause  a  disappearance  of  pus-formation, 
amputation  of  the  offending  portion  of  the  root  will  be 
necessary.  A  heroic  method  of  treating  chronic  ab- 
scesses wdiich  obstinately  refuse  to  heal  is  by  extraction 
and  replantation.  The  method  applies  only  to  single- 
rooted  teeth,  although  it  has  been  successfully  per- 
formed upon  molars.  The  patient's  mouth  is  to  be 
sterilized,  and  the  tooth  extracted.  The  tooth  is  im- 
mediately placed  in  a  solution  of  1  :  1000  mercuric 
chlorid  at  a  temperature  of  120°  F.  It  has  been 
repeatedly  asserted,  but  without  satisfactory  demon- 
stration, that  the  cells  of  the  deeper  layer  of  the 
pericementum  and  the  cementoblasts,  and  also  the 
cement-corpuscles,  retain  their  vitality  for  some  period  after  extrac- 
tion, and  immediate  replantation  results  in  a  re-establishment  of 
the  physiological  union  between  the  teeth  and  alveolus.  It  is  certain, 
however,  that  measures  wdiich  are  necessary  to  thoroughly  sterilize 
the  tooth  before  its  reinsertion  would  be  fatal  to  any  cellular  vitality 

27 


Minim  svringe. 


418  SEPTIC  APICAL  PERICEMENTITIS. 

which  might  exist  in  the  cementam  and  its  covering.  The  pulp- 
canal  is  opened  from  its  apex  and  cleaned  out  with  canal-cleansers,  and 
a  25  per  cent,  solution  of  pyrozone  placed  in  the  canal,  where  it  is 
allowed  to  remain  for  some  time.  In  the  meantime  the  socket  from 
which  the  tooth  has  been  removed  is  syringed  with  pyrozone,  and  should 
the  pericementum  not  adhere  to  the  tooth  the  depth  of  the  socket  is 
scraped  by  means  of  large  spoon-excavators  to  remove  the  tissues  impli- 
cated in  the  abscess.  The  cavity  is  washed  with  pyrozone,  and  a  pledget 
of  cotton,  which  has  been  dipped  in  campho-phenique,  is  placed  in  the 
socket  at  its  bottom.  The  tooth  is  dried  by  means  of  warm  air ;  the  soft 
tissues  at  the  apex,  if  any  be  present,  are  cut  away  for  about  one-eighth 
of  an  inch.  The  canal  is  filled  with  gutta-percha  or  filled  solidly  with 
gold,  the  end  of  the  root  cut  oif  as  far  as  it  has  been  denuded  of  peri- 
cementum, smoothed,  and  returned  to  the  antiseptic  solution.  The 
cotton  is  removed  from  the  tooth-socket,  which  is  syringed  with  3  per 
cent,  pyrozone,  and  the  tooth  returned  to  position.  It  is  tied  to  the 
adjoining  teeth  by  means  of  silk  ligatures  or  held  in  place  by  an  appro- 
priate retaining  appliance. 

A  chronic  abscess  may  discharge  into  the  maxillary  sinus  for  a 
long  period  before  being  discovered,  unless  the  pus-accumulation  be 
extensive,  when  it  escapes  from  the  antrum  into  the  cavity  of  the  nose, 
discharging  by  one  side.  Smaller  accumulations  of  pus  find  exit  in  the 
recumbent  position,  and  attention  is  called  to  one  antrum  as  the  seat  of 
affection  by  noting  that  in  the  morning  pus  appears  at  but  one  nostril. 
The  discharges  from  purulent  nasal  catarrh  appear  upon  both  sides. 

A  more  common  history  of  antral  empyema  is  the  patient's  complaint 
of  dull,  heavy  pains  and  uneasiness  over  one  side  of  the  face,  and  an 
offensive  odor,  which  may  not  be  evident  to  the  operator.  High  illum- 
ination of  the  mouth  by  means  of  the  electric  mouth-mirror  may  reveal 
the  presence  of  fluid  in  the  antrum.  Examination  of  the  posterior  teeth 
will  show  one  of  them  to  be  pulpless.  If  such  a  tooth  be  extracted,  a 
profuse  flow  of  pus  may  follow,  and  a  probe  may  be  passed  through  an 
alveolus  directly  into  the  antrum.  Although  this  is  the  usual  surgical 
relief,  dental  conservatism  rebels  against  the  immediate  condemnation 
of  the  offending  tooth.  Efforts  at  curing  the  antral  condition  through  the 
pulp-canal  are  well-nigh  hopeless — the  antrum  is  entered  at  some  other 
point.  The  tooth  is  treated  as  any  infecting  root ;  is  sterilized  and  filled. 
The  most  certain  spot  of  entry  to  the  antrum  is  about  one-quarter 
inch  above  the  buccal  roots  of  the  upper  first  molar.  The  part,  or  the 
patient,  is  anaesthetized,  and  the  soft  tissues  incised  or  a  section  removed 
by  means  of  a  tubular  knife  ;  a  drill  or  trephine  at  least  one-eighth  inch 
in  diameter,  driven  rapidly,  is  passed  upward,  backward,  and  inward, 
piercing  the  thin  shell  of  the  antrum  at  this  point.     The  nozzle  of  an 


CHRONIC  ALVEOLO-DENTAL  ABSCESS   WITH  FISTULA.        419 


atomizer,  filled  with  a  3  per  cent,  solution  of  pyrozone,  which  has  been 
rendered  alkaline  by  sodium  dioxid  and  warmed,  is  ])assed  into  the 
antrum  and  the  cavity  is  freely  sprayed.  A  probe  is  passed  into  the 
cavity  and  an  exploration  made;  to  detect  the  presence  of  any  dead  bone, 
which,  if  found,  must  be  removed,  the  cavity  of  entrance  being  enlarged 
to  permit  its  removal.  Tiie  cavity  is  sprayed  about  every  other  day 
with  very  dilute,  warm  Dobell's  solution. 

In  cases  of  long-standing  chronic  abscess,  with  fistula  opening  at  a 
distance,  the  fistula  may  refuse  to  heal.  In  that  event  the  tract  should 
be  scraped  and  painted  with  20  per  cent,  silver  nitrate  solution.  If 
healing  does  not  occur,  the  offending  tooth  should  be  extracted. 

In  fistulffi  discharging  upon  the  face  the  formation  of  scar-tissue  may 
bind  the  tissue  of  the  cheek  tight  to  the  bone.  When  this  occurs 
beneath  the  tip  of  the  chin,  the  scar,  after  healing,  usually  resembles 
a  dimple,  and  calls  for  no  interference.  The  scar  and  binding  down 
along  the  border  of  the  inferior  maxilla,  or  beneath  the  malar  bone 
in  the  upper  maxilla,  may  produce  deformity  calling  for  remedy  (Figs. 
326  and  327).     Black's  operation   is   to   be   performed  to   lessen  the 

Fig.  326. 


Fig.  327. 


Scar  caused  by  alveolar  abscess  discharg 
ing  on  the  face.    (Black.) 


Operation  lor  the  itmedy  of  scar   on  the  face 
caused  by  alveolar  abscess.     (Black.) 


deformity,  for  its  complete  correction  is  not  practicable.  A  finger 
placed  in  the  mouth  draws  the  cheek  away  from  the  alveolar  wall,  when 
the  exact  position  of  the  cord  of  attachment  is  discovered.  A  tenotome- 
knife  is  passed  into  the  tissues,  dividing  the  band  of  attachment ;  a  long 
pin  is  passed  through  the  most  depressed  portion  of  the  scar,  its  centre, 
the  long  ends  of  the  pin  resting  upon  the  face  ;  strips  of  adhesive  plaster 
laid  upon  the  skin  under  the  head  and  point  of  the  pin  will  prevent 
the  latter  sinking  into  the  soft  tissues.  The  pin  is  retained  for  several 
days,  until  the  cut  in  the  mouth  heals. 


420 


SEPTIC  APICAL  PERICEMENTITIS. 


Fig.  328. 


Chronic  Septic  Apical.  Pericementitis  (Non-purulent). 

Continued  inflammation  of  a  low  grade,  or  what  may  in  reality  be 
continued  atonic  liypersemia,  may  exist  in  the  apical  pericementum  for 
long  periods  without  pus- formation. 

Cause. — The  cause  of  the  condition  is  the 
presence  of  decomposing  matter  about  the  apex 
of  the  root.  This  is  most  frequently  associated 
with  imperfect  root-fillings.  After  apparent  ster- 
ilization of  canals,  their  filling  has  not  been  com- 
plete, so  that  serum  percolates  into  the  canal  and 
in  all  probability  mixes  with  decomposing  tubuli- 
contents.  As  noted  on  p.  389,  it  requires  a  longer 
time  and  more  complete  and  stronger  antisepsis 
to  completely  sterilize  canals  than  are  usually 
given.  Miller's^  experiments  have  shown  that 
the  infection  of  root-tubuli  is  only  for  a  scant 
depth  (Figs.  328  and  329),  and  that  minute  frag- 
ments of  the  pulp  itself  must  be  regarded  as  the 
offending  agents.  It  is  only  by  way  of  the  pulp- 
canal  that  infection  need  be  feared.     The  depth 


Fig.  o28.— Sector  of  a  cross-section  from  a  diseased  root:  a,  cement;  6,  stratum  granulosum; 
c,  very  narrow  and  finely  branched  tubules.    X  150. 

Fig.  329.— Dentin  from  the  root  of  an  abscessed  tooth,  showing  the  penetration  of  cocci  to  a 
depth  of  about  ^^  mm.  (5^5  in.) ;  the  side  a-h  bordered  upon  the  canal.    X  1000.    (Miller.) 

of  bacterial  penetration   into  the  tubuli  will  show  infection   laterally 

1  Dental  Cosmos,  1890. 


CHRONIC  SEPTIC  APICAL  PERICEMENTITIS.  421 

through  tul)ali  and  ccmentum  to  be  highly  improbable.  A  chronic 
inflammation  is  usually  noted  in  connection  with  non-carious  teeth 
whose  pulps  have  died  in  consequence  of  injury  to  the  apical  vessels. 

Symptoms  and  Diagnosis. — The  symptoms  of"  this  condition  are 
tenderness  upon  decided  pressure  or  upon  percussion  ;  the  response  may 
only  be  elicited  by  pressure  or  percussion  in  one  direction.  The  tooth 
gives  a  dull  note  upon  percussion  and  is  usually  looser  than  its  neigh- 
bors. The  red  line  of  the  gum  extends  farther  toward  the  gum-margin 
than  normal — quite  to  it  in  some  cases.  Evidences  of  a  dead  pulp  are 
sought ;  large  fillings,  the  presence  of  opacity  in  the  tooth,  or  a  mark- 
edly different  color  from  that  of  its  neighbors,  all  point  to  this ;  which 
an  examination  with  the  reflected  light  of  an  electric  mouth-mirror  con- 
firms. The  tooth  by  this  light  is  seen  to  differ  in  opacity  from  its 
neighbors. 

An  effective  method  of  application  of  the  thermal  test,  is  that  sug- 
gested by  M.  L.  Rhein  :  the  tooth  is  isolated  and  a  spray  of  methyl 
chlorid  is  directed  against  it.  A  live  pulp  responds  immediately  to 
the  intense  cold  produced  ;  a  dead  pulp  fails  to  respond. 

Examination  of  the  tooth  is  made  to  see  whether  it  occludes  im- 
properly ;  if  a  filling  be  present,  whether  the  latter  show  occlusion- 
marks  ;  excessive  occlusion  gives  rise  to  symptoms  resembling  those 
of  chronic  septic  apical  pericementitis.  If  faults  in  this  direction 
exist,  they  are  to  be  corrected  and  the  effect  noted.  If  they  do  not 
exist,  a  septic  origin  is  diagnosed. 

Treatment. — The  treatment  is  that  of  pulp-gangrene  :  the  tooth  is 
sterilized  and  isolated,  and  its  root-canals  entered  to  the  apex  and 
sterilized.  The  presence  of  decomposing  organic  matter  is  shown  by  the 
bubbling  Avhich  ensues  when  a  25  per  cent,  solution  of  pyrozone  is 
placed  in  the  canals.  Canal-fillings  are  removed  even  when  apparently 
perfect.  The  condition  is  common  under  cotton  canal-dressings,  the 
latter  usually  emitting  an  offensive  odor.  Gutta-percha  stoppings  are 
warmed  by  blasts  of  hot  air  and  removed  by  fine  hooks.  Oxychlorid 
fillings  are  removed  by  means  of  sulfuric  acid,  which  is  also  applied  to 
all  fine  canals  containing  no  fillings.  Gold,  tin,  and  amalgam  root- 
fillings  are  practically  irremovable.  A  careful  examination  is  always  to 
be  made  for  extra  canals. 

There  can  be  no  assurance  of  safety  until  a  fine  canal-cleanser  can  be 
carried  to  the  apex  of  the  root,  until  the  patient  winces.  The  cleansing  is 
to  be  accomplished  with  strong  sodium-dioxid  solutions.  In  case  of  failure 
to  reach  the  apex,  after  a  prolonged  cleansing  with  sodium  dioxid,  the 
canal  is  washed  out  Avith  a  solution  of  hydrochloric  acid,  a  zinc  electrode 
inserted  in  the  root,  and  a  cataphoric  current  applied  ;  the  zinc  oxy- 
chlorid  formed  is  forced  into  all  interstices.     This  action  should  not 


422  SEPTIC  APICAL  PERICEMENTITIS. 

be  prolonged,  or  the  pericementum  may  become  very  much  irritated  by 
an  excessive  amount  of  the  zinc  salt.  Such  canals  are  best  filled  by 
first  thoroughly  drying,  then  flowing  into  them  the  melted  paraffin  and 
aristol  mixture,  and  thrusting  into  the  fluid  filling  a  long,  slender, 
metallic  point,  made  hot. 

If  the  pericementitis  have  been  of  long  standing,  the  thickening  of  the 
membrane  will  have  caused  protrusion  of  the  tooth.  The  tooth  should  be 
ground  off  at  its  point  of  occlusion  until  it  occludes  with  somewhat  less 
force  than  its  neighbors,  the  therapeutic  principle  in  these  cases  being 
that  of  removing  the  source  of  irritation  and  procuring  surgical  rest. 
Indications  of  favorable  results  are  found  in  the  red  gum-line  assuming 
its  normal  jiosition,  tenderness  disappearing,  and  increased  tightness  of 
the  tooth. 

This  affection  is  extremely  common  about  the  roots  of  pulpless  teeth, 
and  always  signifies  more  or  less  enforced  disuse  of  the  teeth,  and,  if 
uncorrected^  their  ultimate  loss. 


CHAPTER   XXIII 


NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS. 

Apical  and  general  pericemental  disturbances  of  a  vascular  type 
and  of  non-septic  origin  present  in  two  classes,  the  acute  and  the  chronic. 
For  purposes  of  classification  they  may  be  grouped  as  follows  : 


Acute 


Blows. 
Wounds. 
*   Wedo;in2:. 
Orthodontia. 


Chronic 


Non-septic. 
I  Septic. 

Canal  medicaments. 


Acute  also. 


Traumatic  pericementitis 


Perforated  roots 

Chemical  agencies 
Perforated  roots. 
Excess  of  root-filling 
Excess  of  crown-filling 
Resorption  of  roots. 
Hypercementosis  (exostosis). 

r  Traumatisms. 
Over-use  of  teeth 
Misuse  of  teeth 
Disuse  of  teeth 
Impacted  third  molars 
Drug-action. 
Gout. 
Scurvy. 
Syphilis. 


Traumatic  Pericementitis. 

By  traumatic  pericementitis  is  meant  an  inflammation  (profound  irri- 
tation) of  the  pericementum,  the  result  of  mechanical  violence.  Accord- 
ing to  the  nature  and  mode  of  action  of  the  injurious  force,  the  apical 
or  any  other  part,  or  all  parts,  of  the  pericementum  may  be  affected. 
^  Causes. — The  causes  of  this  condition  are  many  and  varied ;  a 
transient  traumatic  pericementitis  may  be  excited  after  arsenical  appli- 
cations to  kill  the  pulp,  by  forcibly  removing  the  pulj)  while  it  still 

423 


General     Aseptic 
Pericementitis 


>  Mal-occlusion. 

>  Non-occlusion. 


424       NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS. 

retains  a  vital  connection  at  the  apex ;  by  forcing  the  root-filling 
material  beyond  the  apex  of  the  root,  particularly  if  the  material  be  of 
an  irritating  character,  such  as  zinc  oxychlorid.  The  presence  of  a 
neutral  canal-filling  projecting  into  the  pericementum  usually  causes  a 
continued  pericementitis  of  a  lower  grade. 

The  passage  of  irritating  chemical  substances  used  in  sterilizing  canals 
may  light  up  a  transient  pericementitis.  Pericementitis  following  the 
introduction  of  sodium-dioxid  or  sulfuric-acid  solutions  usually  sub- 
sides quite  promptly ;  if  strong  solutions  of  zinc  chlorid  or  mercuric 
chlorid  have  caused  the  inflammation,  it  may  be  more  pronounced  and 
of  longer  duration. 

The  passage  of  reamers  through  some  lateral  aspect  of  a  root  may 
light  up  a  pericementitis  which  resists  all  treatment.  These  cases,  fre- 
quently, are  infected  either  at  the  time  of  injury  or  at  a  later  period. 

Too  violent  wedging  is  always  followed  by  more  or  less  pericemen- 
titis of  the  wedged  teeth  and  their  neighbors,  more  marked  when  elastic 
rubber  wedges  are  used. 

In  correcting  irregularities  of  the  teeth,  if  they  be  moved  too  rapidly, 
are  not  firmly  directed  during  the  operation,  or  subsequently  not  firmly 
maintained  in  position,  pericementitis  of  a  high  grade  is  frequently 
excited. 

The  excessive  use  of  the  mallet  in  building  down  fillings,  particularly 
upon  pulpless  teeth,  may  be  followed  by  pericementitis. 

The  biting  of  hard  substances,  such  as  nuts  and  pieces  of  ice,  and 
notably  thread -biting,  are  prolific  sources  of  traumatic  pericementitis. 

In  addition  to  these,  falls,  blows  received  upon  the  teeth,  and  blows 
received  under  the  chin,  bringing  the  teeth  forcibly  together,  all  induce 
pericementitis,  which  may  vary  in  degree  from  a  passing  soreness  to 
general  osteitis  and  perhaps  necrosis. 

Prophylaxis. — It  will  be  observed  that  the  majority  of  these  causes 
are  associated  with  operative  dental  manipulations,  or  dental  abuse  by 
the  patient,  and  are  in  a  large  degree  preventable.  In  treating  pulp- 
canals  with  such  agents  as  a  50  per  cent,  solution  of  sodium  dioxid,  or 
a  50  per  cent,  solution  of  sulfuric  acid,  care  is  taken  as  the  end  of  the 
canal  is  approached  not  to  pump  them  through  the  apex,  and  to  neu- 
tralize, with  an  acid  in  one  case,  an  alkali  in  the  other,  at  the  end  of  the 
sitting.  Strong  solutions  of  zinc  chlorid  or  mercuric  chlorid  are  kept 
away  from  the  apices  of  roots.  In  case  zinc  oxychlorid  is  used  as 
a  canal-filling,  the  apex  of  the  root  is  gently  sealed  with  a  small  pellet 
of  cotton  containing  an  antiseptic  oil,  or,  better,  a  small  cone  of  softened 
gutta-percha.  Canal-fillings  are  inserted  gently  and  withdrawn  as  soon 
as  sensitivity  is  noted  ;  by  introducing  too  large  a  root-filling  mass,  air 
may  be  imprisoned  between  the  filling  and  the  apex  of  the  root,  exciting 


TRAUMATIC  PERICEMENTITIS.  425 

a  reaction  as  though  the  filling  itself  had  been  passed  through  the  apical 
foramen.  Teeth  are  to  be  supported  mechanically  while  large  gold-fill- 
ings are  being  malloted  into  them.  The  support  is  derived  through 
judicious  placing  of  wedges.  Severe  malleting  should  not  be  practised 
except  the  pericementum  be  healthy. 

Gradual  wedging  should  supplant  the  violent  wedging  with  rul)l)er. 
The  latter,  when  used  at  all,  should  be  in  thin  layers,  and  the  wedging 
completed  with  tape  or  wooden  wedges  lightly  applied.  Malleting 
should  not  be  done  upon  wedged  teeth  until,  after  a  period  of  rest,  ])eri- 
cementitis  has  subsided,  and  unless  the  teeth  are  rigidly  held  during  the 
filling  operation. 

Orthodontic  appliances  should  be  of  such  types  as  permit  a  gradual, 
steady  advance  in  tooth-movement ;  and  when  the  irregularity  is  cor- 
rected the  tooth  should  be  maintained  firmly  in  its  new  position  until 
the  surrounding  tissues  hold  it  firmly. 

Patients  should  be  warned  against  the  evil  effects  of  thread-biting 
and  biting  hard  substances. 

Symptoms  and  Diag-nosis. — The  general  symptoms  are  soreness 
and  looseness  of  the  tooth,  together  with  varying  degrees  of  vascular 
disturbance  of  the  gum  overlying  the  tooth.  A  diagnosis  may  usually 
be  made  by  obtaining  a  history  of  the  case,  by  excluding  septic  influ- 
ences as  probable  causes,  and  by  the  disappearance  of  the  disorder  upon 
applying  treatment  indicated  in  traumatic  injuries. 

Clinical  History. — Cases  due  to  the  passage  of  irritating  chemical 
substances  through  the  root-apex  subside,  as  a  rule,  after  a  period  of  a 
few  days.  Cases  due  to  the  presence  of  a  protruding  root-filling  usually 
become  chronic,  and  secondary  pathological  processes  arise.  Cases  due 
to  wedging  subside,  as  a  rule,  after  a  period  depending  upon  the  severity 
of  the  wedging  and  peculiarities  of  the  individual.  Permanent  injury 
may  be  done  to  pericementum  from  such  causes,  and  a  predisposition 
to  degenerative  changes  be  established.  The  pericementum  may  be- 
come permanently  debilitated  and  perfect  tissue-regeneration  or  organi- 
zation be  prevented  in  tooth-regulating,  if  the  teeth  are  permitted  undue 
mobility  during  regulating  or  not  firmly  splinted  afterward.  In  cases 
due  to  direct  and  sudden  violence  to  the  pericementum,  blows  upon  the 
teeth,  and  the  crushing  of  hard  bodies,  etc.,  the  acute  symptoms  may 
disappear  after  a  period  governed  by  the  degree  of  violence  and  of  tis- 
sue-reaction. In  these  cases,  however,  and  in  those  of  thread-biting, 
strangulation  or  thrombosis  of  the  pulp-vessels  may  occur  in  conse- 
quence of  the  pericementitis,  and  at  later  periods  pulp-decomposition  may 
occur  and  give  rise  to  the  septic  forms  of  pericementitis. 

Patholog-y  and  Morbid  Anatomy. — In  cases  caused  by  the  action 
of  irritating  chemicals,  the  latter  cause  destruction  of  an  amount  of 


426        NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS. 

tissue,  and  the  vascular  system  and  cells  react  to  remove  the  dead  tissue. 
The  amount  of  tissue-death  depends  directly  upon  the  amount  of  the 
chemical  present,  the  vascular  reaction  being  in  correspondence.  Pre- 
sumably the  pericementitis  persists  in  some  degree  until  the  foreign 
(dead)  material  is  removed  by  natural  processes. 

An  excess  of  root-filling  material  introduces  a  foreign  body  into  a 
sensitive  vascular  tissue,  and  presumably  the  changes  noted  as  due  to  the 
presence  of  foreign  bodies  in  other  parts  occur — an  attempt  at  removal 
by  phagocytes  and  subsequent  encystment  (see  Resorption  of  Roots  and 
Hypercementosis). 

In  cases  due  to  traumatism,  such  as  violent  wedging,  rapid  move- 
ment in  regulating,  overmalleting,  blows,  thread-,  ice-,  and  nut-biting, 
etc.,  the  condition  is  surgically  one  of  bruise. 

The  phenomena  of  active  inflammation  make  their  appearance  to  an 
extent  governed  by  the  degree  of  violence — exudation,  swelling,  red- 
ness, and  pain  ;  fibrinous  and  corpuscular  exudations  occur,  and  later  a 
reorganization  of  tissue  occurs,  in  some  cases  a  degeneration,  depend- 
ing upon  the  completeness  with  which  the  indicated  therapeusis  is 
applied  and  upon  the  vitality  of  the  patient. 

Traumatic  pericementitis  in  high  degree  in  the  young  may  be  recov- 
ered from  ;  but  in  the  middle-aged  and  aged  it  may  give  rise  to  a  series 
of  degenerative  changes  which  only  end  with  the  loss  of  the  tooth. 

Cases  due  to  perforation  of  the  root  and  wounding  of  the  pericemen- 
tum, after  the  acute  symptoms  have  passed,  commonly  assume  an  irri- 
tative and  chronic  type,  the  soft  tissues  included  in  the  perforation  being 
in  a  state  analogous  to  an  ulcer.  Many  of  these  cases  become  infected 
owing  to  the  difficulty  of  completely  sterilizing  the  apical  portion  of  the 
canal  which  lies  beyond  them. 

Treatment. — If  the  cause  of  the  condition  be  still  in  action,  it  is 
to  be  removed  or  neutralized.  In  all  cases  due  to  violence  the  treat- 
ment is  that  adapted  to  injury  ;  first,  surgical  rest  of  the  pericementum. 
This  may  be  accomplished  in  two  ways  ;  either  by  preventing  the  tooth 
striking  its  antagonists,  or  holding  it  so  rigidly  that  it  cannot  move  if  it 
does  meet  them.  As  a  preliminary  measure  the  tooth  is  gently  but 
firmly  lashed  to  its  neighbors  by  means  of  ligatures  so  that  it  is  rigidly 
held.  A  swaged  cap  is  either  fitted  to  a  neighboring  tooth,  or  the 
antagonizing  teeth  are  ground  away  until  they  fail  to  strike  the  injured 
tooth ;  the  first  method  is  to  be  preferred. 

In  cases  involving  several  teeth,  such  as  all  of  the  incisors,  two  me- 
tallic plates  are  quickly  swaged  to  cover  the  posterior  teeth  and  they 
are  cemented  in  position. 

Cases  due  to  mild  injury  may  disappear  after  painting  the  overlying 
gum  and  surrounding  territory  with  tincture  of  iodin. 


CHRONIC  APICAL  PERICEMENTITIS.  427 

A  mouth-wash  Avhich  affords  marked  relief  in  many  cases  is  extract 
of  haraamelis,  used  in  one-half  strength  several  times  a  day. 

Acute  pericementitis  due  to  the  passing  of  a  canal-reamer  into  some 
lateral  aspect  of  the  pericementum  may  occur  once  in  the  history  of  a 
practitioner ;  it  never  should  twice.  Reaming  should  be  done  with 
such  care  and  deliberation  that  the  operator  is  certain  of  the  direction 
taken  by  the  reamer,  and  he  should  be  prepared  to  cease  reaming  as 
soon  as  canal  curvature  is  felt.  Before  a  reamer  removes  the  last 
portion  of  cementum,  separating  the  instrument  from  the  pericementum, 
sensitivity  is  announced  by  the  patient,  and  tiie  reaming  should  cease  at 
once.  Before  reaming  any  canal,  its  length  and  direction  should  be 
recorded  by  measuring  upon  a  soft,  fine  broach.  Should  sensation  and 
bleeding  occur  before  this  end  is  attained,  the  root  has  been  perforated. 
Sterilization  of  the  canals  has  presumably  preceded  the  reaming  opera- 
tion ;  if  not,  the  difficulty  is  increased  owing  to  the  impracticability  of 
thoroughly  sterilizing  the  portion  of  the  canal  beyond  the  perforation. 
The  canal  is  syringed  freely  with  a  styptic  antiseptic  ;  for  this  purpose 
nothing  is  better  than  phenol  sodique.  As  soon  as  bleeding  ceases,  the 
canal  is  to  be  filled  with  some  unirritating  material  which  can  be  placed 
without  exercising  pressure  ;  chloro-percha  or  the  paraffin  mixture  meets 
the  indication.  Either  filling  is  flowed  into  the  canal  until  it  is  full, 
and  a  central  core,  a  cone  of  gutta-percha,  is  gently  inserted  in  the 
fluid  filling. 

If  evidences  of  persistent  pericementitis  are  noted  about  the  root 
after  this  operation,  it  may  be  inferred  that  either  the  portion  of  canal 
beyond  the  perforation  is  unsterilized  or  unfilled,  or  that  the  perice- 
mentum protests  against  the  presence  of  the  root-filling.  Guilford  ^  has 
advised  and  practised  successfully  in  these  cases  amputation  of  the  por- 
tion of  the  root  beyond  the  perforation. 

Chronic  Apical  Pericementitis  (Non-septic). 

Definition. — A  non-infective  condition  produced  by  the  action  of  a 
constant  irritant  about  the  apex  of  a  tooth-root. 

Causes. — Many  of  the  causes  of  acute  inflammation,  if  of  less 
intensity  and  continuous,  or  frequently  repeated,  give  rise  to  the  chronic 
condition.  Prominent  among  these  is  the  thread-biting  habit.  Another 
frequent  cause  is  an  overfull  filling ;  a  filling  projects  in  such  manner 
that  it  receives  an  excessive  impact  during  mastication.  A  projecting 
root-filling  of  any  substance,  causes  continued  irritation  of  the  peri- 
cementum into  which  it  projects.  An  analogous  condition  may  exist  in 
perforated  roots  which  have  been  filled. 

Symptoms. — The  symptoms  of  the  condition  are  redness  of  the 

^  Proc.  Academy  of  Stomatology,  1897. 


428        NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS. 

overlying  gum,  tenderness  upon  percussion,  and  some  degree  of  loose- 
ness of  the  tooth. 

Effects. — The  effects  of  this  condition  may  vary  according  to  the 
extent  of  the  irritation  and  its  duration.  The  irritation  may  in  point 
of  eifect  be  but  a  continued  stimulation  of  slight  or  high  degree,  in 
which  event  the  effects  of  stimulation  follow — i.  e.,  prolonged  arterial 
hypersemia  and  its  results.  The  condition  may  be  one  of  over-stimula- 
tion or  irritation  proper,  with  corresponding  results.  There  is  much 
evidence  to  show  that  the  degree  and  quality  of  irritation  vary.  In- 
flammatory degeneration  may  occur — i.  e.,  a  formation  of  embryonic 
tissue  which  fails  of  complete  organization,  or  degenerates.  The  debili- 
tated part  may  become  infected. 

Diag-nosis  and  Prog-nosis. — The  diagnosis  of  the  condition  itself  is 
usually  made  without  difficulty,  but  its  nature  and  causes  may  at  times 
be  very  obscure  or  difficult  of  detection.  It  is  observed  whether  some 
part  of  a  filling  or  of  the  tooth  itself  receives  undue  impact  in  mastica- 
tion ;  if  so,  the  redundant  substance  is  ground  away,  and  the  effect 
noted.  Look  well  to  the  incisors  and  note  whether  they  occlude  cor- 
rectly. A  history  of  the  case,  when  obtainable,  is  of  first  importance. 
Knowledge  of  the  nature  and  thoroughness  of  the  canal-filling,  the 
medicaments  used,  etc.,  is  a  valuable  guide.  The  discovery  of  the 
cause  of  the  condition  can  only  be  made  by  exclusion  ;  possibly  exist- 
ing causes  are  excluded  one  by  one,  in  the  order  of  their  probability. 

The  prognosis  of  the  case  will  depend  upon  the  completeness*  with 
which  the  exciting  cause  of  the  condition  can  be  removed,  and  the  char- 
acter of  the  pathological  changes  which  have  occurred. 

Treatment. — The  treatment  of  the  condition  consists  in  the  removal 
of  the  cause,  and  giving  surgical  rest.  When  this  is  done,  provided  no 
secondary  pathological  processes  have  arisen,  the  pericementum  recovers. 
The  occurrence  of  this  condition,  due  to  traumatism  about  unfilled  roots, 
is  always  a  danger-signal.  The  pulp  should  be  carefully  examined  to 
determine  its  vitality.  Pulps  frequently  die  of  thrombosis  arising  from 
repeated  traumatism  of  the  apical  pericementum,  and  the  conditions 
then  existing,  dead  material  in  proximity  to  tissues  in  a  state  of  hyper- 
semia,  invite  complicated  infections. 

Hypercementosis. 

Definition. — By  hypercementosis  is  meant  a  secondary  deposit,  or 
an  increase  of  volume  of  the  cementum  of  a  tooth  beyond  the  normal 
limit.     It  may  be  circumscribed  or  diffuse. 

Causes. — Its  occurrence  is  frequently  associated  with  continued  non- 
septic  irritation  of  the  pericementum  ;  its  causes,  therefore,  may  be  any 
of  those  described  in  connection  with  chronic  non-septic  pericementitis. 


HYPERCEMENTOSIS. 


429 


It  is  found  associated  witli  other  conditions  hosidc  traumatic  pericemen- 
titis, which  conditions  will  be  discussed  later.  In  other  cases  no  direct 
causes  can  be  ascribed  to  it ;  but  ])ossibilities  in  this  direction  will  be- 
come more  evident  from  a  survey  of  its  probable  ])atholo<j:y.  In  general 
terms,  its  cause  may  be  described  as  a  localized  or  diffused  hyperemia 
of  the  pericementum. 

Pathology  and  Morbid  Anatomy. — The  normal  mode  of  formation 
and  the  history  of  cemental  development  must  be  recalled  to  make 
pathological  formations  intelligible.  The  cementum  is  deposited  as  sub- 
periosteal bone  in  successive  layers,  beginning  before  dentinal  root- 
formation  is  complete. 

For  some  time  after  eruption  of  the  teeth  the  cementum  consists  of 
but  few  lamellae  of  deposit.     It  differs  from  bone  in  that  its  corpuscles, 


Fig.  330. 


imprisoned  cementoblasts,  are  irregularly  distributed.     The  cementum 
is  deposited  throughout  life,  so  that  the  teeth-roots  of  aged  persons  are 


r/^. 


/."Krtrt-- 


FiG.  331. 


•  ///A^jm,,,.^ 


'-^h 


......„...„™....ilMMi 


Hypertrophy  of  the  cementum  on  the  side  of  a  root  of  a  lower  molar  near  the  neck  of  the  tooth  of 
a  man :  a,  dentin  :  6,  cementum  :  c,  fibres  of  peridental  membrane  ;  from  6  to  c  the  cementum  is 
normal  and  the  incremental  lines  fairly  regular,  but  at  d  one  of  the  lamellre  is  greatly  thickened ; 
at  e  this  lamella  is  seen  to  be  about  equal  in  thickness  with  the  others.  The  next  two  lamella? 
are  thin  over  the  greatest  prominence,  but  one  is  much  thickened  at  g,  and  both  at  h.  These 
latter  seem  to  partially  fill  the  valleys  which  were  occasioned  by  the  first  irreguhir  growth. 
From  a  lengthwise  section.    (Black.) 

covered  with  thick  layers  of  cementum.    The  maximum  of  deposition  is 
noted  about  the  apices  of  the  roots,  the  deposits  gradually  merging  into 


430        NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS. 

Fig.  332. 


WMmiimmmjimmii:: 

Hj'pertrophy  from  root  of  a  cuspid  in  a  man,  in  which  the  irregularity  is  confined  to  the  first  lamellae: 
a,  dentin ;  6,  thickened  first  lamella ;  c,  subsequent  lamellae,  which  are  seen  to  be  fairly  reg- 
ular.   (Black.) 

the  thin  lamella  of  the  neck.     The  deposits  occur  in  successive  lavers 
or   lamellse.      The    formative   activity   of    the    cement  am,    therefore, 

Fig.  333. 


Apex  of  root  of  an  upper  bicuspid  tooth  with  irregularly  developed  cementum :  a,  ci,  dentin ;  5,  b, 
pulp-canals.  The  lamellae  of  cementum  are  marked  1,  2,  3,  etc. ;  d,  rf,  d,  absorption-areas  that 
have  been  refilled  with  cementum.  "it  will  be  seen  that  the  apices  of  the  roots  Avere  originally 
separate,  but  became  fused  with  the  deposit  of  the  second  lamella  of  cementum,  and  that  in 
this  the  regular  growth  began  and  was  most  pronounced.  It  has  continued  through  the  sub- 
sequent lamellae,  but  in  less  degree.  It  will  also  be  noticed  that  the  absorption-areas,  d,  d,  d, 
have  proceeded  from  certain  lamellae.  That  between  the  roots  has  broken  through  the  first 
lamella  and  jjenetrated  the  dentin,  and  has  been  filled  with  the  deposit  of  a  second  lamella, 
other  of  the  absorptions  have  proceeded  from  lamellae  which  can  be  readily  made  out.  The 
small  points,  e,  seem  to  have  been  filled  with  the  deposit  of  the  last  layer  of  the  cementum, 
while  others  have  one,  two,  or  more  layers  covering  them.    (Black.) 

normally  persists  to  old  age,  and,  like  any  other  function,  is  suscepti- 
ble of  alterations.      It  is  difficult,   therefore,  to   state   exactly  where 


HYPERCEMENTOSIS.  431 

pathological  hypertrophy  begins,  and  physiological  new  formation 
ends.  Nodular  and  irregular  forms  arising  from  the  general  surface  are 
clearly  of  abnormal  type.  They  exist  as  distinct  nodular  projections 
upon  some  lateral  aspect  of  the  pericementum,  as  a  globular  mass  at 
the  apex  of  the  root,  or  generally  diffused  over  a  greater  or  less  surface 
of  the  root  (Fig.  330).  Each  of  these  probably  arises  from  different 
causes.  Figs.  331,  332,  and  333,  exhibit  the  histological  characters 
of  the  new  growth.  Outlined  portions  of  the  pericementum  are  seen 
to  have  exercised  their  cement-forming  function  and  caused  deposits 
of  successive  lamellse  of  cementum,  in  which  the  cement-corj)uscles  are 
irregularly  distributed  as  in  normal  cementum.  Areas  are  seen  where 
portions  of  pre-existing  cementum  have  undergone  resorption,  and 
where  redeposition  of  cementum  has  occurred — two  distinct  vital  pro- 
cesses. It  is  evident  that  as  a  result  of  some  irritating  influence  an 
outlined  portion  of  the  pericementum  has  been  the  seat  of  stimulation  ; 
its  vital  activities  have  been  increased,  and  the  energy  expended  in  for- 
mative activity  of  the  cementoblasts.  This,  it  will  be  observed,  is  in  other 
parts  the  outcome  of  continued  arterial  hyperemia  and  increased  func- 
tional activity,  commonly  the  consequence  of  an  overwork  which  is 
followed  by  periods  of  rest.  The  inference  that  some  spot  of  mal-occlu- 
sion  of  a  tooth,  acting  as  a  periodical  irritant,  is  a  probable  causative 
agent,  is  clear.  Drawing  an  analogy  from  other  parts,  the  altered  physi- 
ology concerned  in  hypercementosis  is  a  mild  periodical  irritation  of  a 
more  or  less  localized  portion  of  the  pericementum. 

It  is  seen,  therefore,  how  faulty  occlusion  at  some  point  of  a  tooth- 
crown  may  cause  overstraining  of  the  pericementum  at  a  point  opposite 
to  that  of  faulty  impact.  Also,  how  a  root-filling,  such  as  a  pro- 
jecting cone  of  gutta-percha,  may  excite  reaction,  and  at  points  of 
pericementum  distant  from  the  apex,  a  constant  mild  irritation  (by  con- 
tinuity) exist  in  degree  sufficient  to  produce  hypertrophy.  Again,  in 
other  directions,  any  cause  capable  of  exciting  irritation  of  the  peri- 
cementum at  or  near  the  neck  of  a  tooth,  may  cause  a  vascular  reaction 
of  milder  degree  in  a  more  distant  pai't  of  the  pericementum,  and  thus 
hypertrophy  occur.  Such  causes  are  found  in  the  irritation  induced  by 
the  edges  of  projecting  fillings,  overlapping  of  cavity-margins  by  the 
gum,  or  the  presence  of  deposits  of  salivary  calculi ;  all  of  these  are  in 
the  nature  of  foreign  bodies,  and  act  as  mechanical  irritants.  Hyper- 
cementosis is  a  possibility  in  any  case  of  chronic  pericemental  irritation  ; 
it  represents  a  degree  of  irritation,  not  any  specific  isolated  causes. 

Symptoms  and  Diag-nosis. — As  the  hypertrophy  is  a  result  of 
certain  conditions,  the  symptoms  when  discoverable  are  those  of  the 
causative  conditions.  That  hypercementosis  has  symptoms  of  its  own, 
has  never  been  demonstrated,  although  a  number  of  symptoms  may  be 


432        NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS. 

associated  with  the  condition  and  disappear  with  the  extraction  of  the 
tooth.  The  symptoms  are  so  vague  that  none  of  them  can  be  said  to  be 
pathognomonic  of  hypercementosis.  The  diagnosis  of  this  condition  is 
usually  made  post-mortem  ;  painful  sensations  have  been  experienced, 
the  tooth  has  been  extracted,  and  the  hypertrophy  seen — the  symptoms 
disappeared  with  the  loss  of  the  tooth.  It  is  purely  a  '■'post  hoc  2:)ropter 
hoc"  diagnosis.  The  a:;-ray,  however,  furnishes  a  certain  means  of 
diagnosis. 

Regarding  the  pathology  of  the  disease,  it  is  evident  that  the  symp- 
toms will  be  those  of  a  long-continued  mild  pericementitis.  The  tooth  or 
teeth  are  very  slightly  sensitive  upon  percussion.  The  gum-color  may 
be  unaflPected ;  the  tooth  may  not  be  loosened.  The  patient  complains 
of  a  disposition  to  bite  hard  upon  the  particular  tooth — to  grind  upon  it, 
if  it  be  a  posterior  tooth.  These  symptoms  pointing  to  pericemental 
hypersemia  are  not  necessarily  accompanied  by  hypercementosis,  but 
when  such  teeth  are  extracted  overgrowth  of  the  cementum  is  frequently 
found.  In  many  cases  treatment  directed  to  the  relief  of  the  hypersemia 
causes  all  symptoms  to  disappear ;  that  is,  if  hypercementosis  has 
occurred,  it  has  caused  no  symptoms  after  its  exciting  cause  has  been 
removed. 

Flagg  records^  cases  where  neuralgias  of  the  trigeminus,  painful 
functional  disturbances  of  the  eye  and  ear,  etc.,  have  been  relieved  by 
removing  tooth-roots  or  teeth  which  were  the  seat  of  hypercementosis 
(see  Chapter  XXVIII.).  The  diagnosis  of  pain  about  the  teeth  or  head, 
due  to  cemental  hypertrophy,  can  only  be  made  by  exclusion.  Local 
and  general  causes  of  eye  and  ear  diseases  having  been  excluded,  the 
teeth  should  be  examined  for  sources  of  irritation.  When  these  exist, 
they  are  usually  found  associated  with  pulp-disturbance.  If  pulp-dis- 
ease can  be  positively  excluded,  the  possibility  of  pericemental  irritation 
should  be  taken  into  account.  If  any  one  tooth  show  a  reaction  differ- 
ing from  its  fellows,  exhibiting  pericemental  irritability,  particularly  if 
upon  percussion  any  increase  of  the  reflex  pain  be  noted,  the  tooth 
should  be  extracted,  as  the  possible  cause  of  the  neuralgia.  If  the 
neuralgia  disappear,  it  may  be  fairly  inferred  that  its  origin  was  dental. 
Entire  dentures  have  been  extracted,  tooth  by  tooth,  in  the  vain  endeavor 
to  cure  a  neuralgia  about  the  head.  The  direct  diagnosis  of  hyper- 
cementosis by  symptoms  is,  therefore,  very  uncertain,  and  its  determi- 
nation as  the  causative  condition  of  reflex  neuralgia  still  more  so.  It  is 
only  by  use  of  the  a;-ray  that  the  existence  or  non-existence  of  hyper- 
cementosis can  be  positively  determined  without  extraction. 

Treatment. — Any  tooth  which  shows  evidence  of  chronic  apical  or 
circumscribed  pericementitis,  even  after  all  discoverable  causes  of  such 

^  Dental  Cosmos,  1878. 


RESORPTION  OF  THE  ROOTS  OF  PERMANENT  TEETH.        433 

a  condition  are  removed,  is  usually  condemned  sooner  or  later  to  the 
forceps.  Hyperceraentosis  is  a  possibility,  even  a  probability,  and  its 
causes,  whatever  they  be,  are  still  in  operation.  It  is  evident,  there- 
fore, that  the  longer  the  condition  persists  the  greater  will  be  the 
mechanical  difficulty  in  extracting.  The  extraction,  diffieidt  though 
it  be,  must  be  complete,  or  relief  from  reflex  disturbances  cannot  be 
hoped  for. 

(Other  phases  of  hypercementosis  will  be  discussed  in  connection 
with  general  aseptic  pericementitis.) 

Resorption  of  the  Roots  of  Permanent  Teeth. 

Definition. — By  resorption  of  the  roots  of  permanent  teeth  is  meant 
a  condition  analogous  to  that  observed  upon  the  roots  of  temporary  teeth 
prior  to  the  eruption  of  the  permanent  teeth. 

Pathology  and  Morbid  Anatomy. — Both  resorption  of  cementum 
and  its  redeposition  occur  in  teeth  as  physiological  processes ;  at  some 
aspect  of  the  cementum  the  tissue  becomes  hollowed  out,  and  later 
filled  in  by  new  cementum.  Resorption  of  tissue  throughout  the 
body  is  accomplished  by  means  of  multinucleated  cells.  At  some 
part  to  be  physiologically  resorbed  these  cells  make  their  appearance 
in  contact  with  the  tissue  to  be  removed,  and  it  gradually  disappears, 
the  layer  of  multinucleated  cells  constantly  occupying  the  excavated 
territory. 

If  a  foreign  (aseptic)  body  be  introduced  into  living  tissues,  it 
becomes  surrounded  by  these  cells,  which  in  some  cases  effect  its 
removal ;  in  others,  failing  to  remove  the  foreign  body,  connective 
tissue  forms  about  it  and  encysts  it ;  encystment  may  occur  after  partial 
removal  by  giant  cells.  It  has  been  observed  that  under  conditions  of 
irritation  about  the  necks  of  teeth,  such  as  those  produced  by  the 
presence  of  foreign  bodies,  that  the  hard  dental  tissues  may  become 
excavated  and  deep  depressions  form.  Teeth  whose  roots  have  under- 
gone resorption  present  these  conditions :  any 
amount  of  the  apical  portion  of  the  root  has  dis- 
appeared (Fig.  334),  and  if  the  socket  from  which 
it  has  been  extracted  be  examined,  it  will  be  found 
filled  with  a  mass  of  soft  tissue,  resorption  of  ce- 
mentum, dentin,  and  alveolar  walls  having  occurred. 

Teeth  which   have    been   implanted,   replanted, 
or  transplanted,  about  which  union  more    or  less 
perfect   has   taken    place   (provided    always  that   suppuration   has    not 
occurred),  if  subsequently  extracted,  are  seen  to  have  been  the  seat  of 
tissue-resorption,  showing  excavations  into  the  cementum  and  dentin. 
The  explanation  of  these  cases  is,  no  doubt,  that  of  the  disposal  of  asep- 

28 


434        NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS. 

tic  foreign  bodies.  Teeth  inserted  into  sockets  formed  from  them,  re- 
turned to  their  original  alveoli  after  extraction,  or  taken  from  one  alveo- 
lus and  placed  in  another,  are  of  the  nature  of  foreign  bodies,  but  least 
of  all  so,  when  replanted.  If  alveolus  and  tooth  be  rendered  aseptic,  the 
insertion  of  the  tooth  is  followed  by  the  phenomena  of  mild  inflamma- 
tion ;  exudation,  fibrinous  and  corpuscular,  occurs,  and  the  tissues 
endeavor  to  rid  themselves  of  an  intruding  body  ;  the  inflammatory 
reaction  soon  subsides,  and  giant  multinucleated  cells  attack  the  tooth- 
root  and  endeavor  to  remove  it  by  solution  ;  this  they  accomplish  in  part 
and  in  spots  ;  then  a  tolerance  is  established  and  connective  tissue  organ- 
izes about  the  root ;  later,  more  complete  regeneration  is  represented  in 
formation  of  bone.  It  is  understood  that  in  the  primary  inflammatory 
action  some  portion  of  the  alveolar  wall  undergoes  transformation  into 
embryonic  tissue.  It  will  be  inferred,  therefore,  that  whenever  resorp- 
tion of  roots  occurs  it  indicates  a  degree  of  irritation  in  the  surround- 
ing vital  tissues  probably  in  excess  of  that  producing  local  hypertrophy. 
As  the  process  occurs  most  commonly  in  middle  age,  it  may  also  be 
regarded  as  a  modified  and  hastened  expression  of  alveolar  atrophy. 

Causes. — The  possible  causes  which  may  be  assigned  to  this  condi- 
tion are  naturally  those  associated  with  hypercementosis,  differing  in 
degree.  However,  another  element  must  enter  into  the  matter  to 
determine  the  peculiar  tissue-reaction.  For  want  of  a  better  explana- 
tion these  may  be  called  peculiarities  of  the  individual. 

Some  of  the  cases  exhibit  no  tangible  cause.  Perhaps  the  most 
common  of  the  causes  discoverable  is  a  protruding  root-filling.  This 
condition  has  been  noted  as  the  probable  causative  association  with  the 
peculiar  grade  and  quality  of  pericemental  reaction  involved  in  resorp- 
tion. Cases  occur,  however,  where  the  tooth  is  non-carious  and  the 
pulp  is  alive,  direct  evidence  of  vitality  being  obtained  before  and  after 
■extraction. 

Symptoms. — The  tooth  may  be  tender  upon  percussion,  and  is 
nearly  always  loosened ;  but  unless  the  resorption  have  progressed  far, 
the  latter  may  not  be  observed.  Later  the  loosening  is  peculiar ;  the 
tooth  moves,  as  might  be  expected,  with  a  shortened  radius  of  move- 
ment. The  condition  may  be  discovered  by  accident :  evidences  of 
mild  pericementitis  appear,  and  the  pulp-canal  is  opened  to  search  for 
a  cause.  The  pulp  may  be  found  alive  ;  if  alive,  and  it  is  killed,  or  if  it 
is  found  dead,  broaches  pass  suddenly  into  the  mass  of  soft  tissue  under- 
lying the  root.  The  progressive  loosening  of  the  tooth,  with  a  short- 
ened radius  of  movement,  is  about  the  only  constant  symptom  of  the 
condition. 

In  cases  of  live  pulp  this  organ  may  be  hypersemic,  so  that 
increased  response  to  heat  or  cold  is  felt;    this,  taken  in  connection 


GENERAL  ASEPTIC  PERICEMENTITIS.  435 

with  the  tenderness  npon  jiercnssion  which  can  usually  be  elicited,  and, 
with  the  peculiar  loosening'  of  the  tooth,  is  a  diagnostic  guide. 

Flagg^  states  that  reflex  neuralgias  occur  in  this  condition,  but  that 
the  most  constant  indication  noted  by  him  was  a  sense  of  discomfort 
about  the  jaws,  vaguely  associated  with  some  one  tooth.  The  patient 
was  convinced  that  if  the  tooth  were  removed,  relief  would  follow. 

In  the  absence  of  the  peculiar  loosening  of  the  tooth,  which  may 
not  occur  until  the  root  is  nearly  gone,  a  diagnosis  is  made  by  exclusion  ; 
the  resorption  is  most  commonly  discovered  by  entering  the  pulp-canal 
and  finding  its  length  much  shortened. 

If  the  apparatus  be  available,  the  ;r-ray  should  exhibit  the  condition 
with  sufficient  clearness  to  furnish  an  absolute  diagnosis. 

Treatment. — Whether  the  condition  be  discovered  or  not,  every 
possible  source  of  pericemental  irritation  should  be  removed.  Usually 
this  involves  the  entrance  to  and  complete  cleansing  of  the  pulp- 
chamber  ;  when  the  existence  of  a  mechanical  irritant  in  a  protruding 
root-filling,  a  broken  broach  or  reamer  projecting  beyond  the  apex,  is 
discovered  and  removed.  If  pain  continue,  or  neuralgia  assignable  to 
no  other  cause  persist  after  removal  of  all  discoverable  sources  of 
pericemental  disturbance,  the  tooth  should  be  extracted. 

General  Aseptic  Pericementitis. 

Definition. — By  general  aseptic  pericementitis  is  meant  a  vascular 
disturbance  involving  all  or  the  greater  part  of  the  pericementum,  and 
not  due  to  septic  causes.  Pericementitis  is  a  misnomer  in  this  connec- 
tion, for  in  some  of  the  cases  the  essential  phenomena  of  inflammation 
may  not  be  present.     The  condition  may  be  acute  or  chronic. 

ACUTE    variety. 

Causes. — The  causes  of  acute  general  pericementitis  are  mechanical 
violence,  the  irritation  of  foreign  bodies,  notably  improperly  adapted 
artificial  crowns,  selective  drug-action,  and  gout. 

Symptoms. — The  symptoms  of  the  condition  are  tenderness  or  pain 
upon  pressure  or  percussion,  loosening  of  the  tooth,  with  injection  of 
the  overlying  gum  ;  the  swelling,  like  the  other  symptoms,  is  less  pro- 
nounced than  in  septic  pericementitis. 

Clinical  History. — Cases  already  described  as  due  to  too  violent 
wedging,  abuses  in  regulating  of  teeth,  are  fitly  included  under  this 
head,  as  are  also  many  cases  due  to  direct  violence,  such  as  blows. 
When  artificial  crowns  of  the  barrel  variety  are  driven  too  far  under 
the  gum,  their  edges  may  impinge  upon  the  pericementum  and  give  rise 
to  inflammation,  which  may  involve  the  greater  portion  of  the  peri- 

^  Lectures. 


436        NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS. 

cementum.  Bristles  from  tooth-brushes,  fragments  of  tooth-picks,  and 
other  material  may  be  driven  forcibly  into  the  pericementum  and  cause 
inflammation.  In  all  of  these  cases,  beginning  at  the  gum-margin  or 
communicating  with  the  mouth-cavity,  septic  infection  almost  certainly 
follows. 

If  mercury  be  administered  to  patients  in  large  doses  for  long  periods, 
or  in  one  or  more  massive  doses,  or  if  the  patient  have  an  idiosyncrasy 
to  the  action  of  this  agent,  an  irritation  of  the  salivary  glands  is  ex- 
cited, followed  by  looseness  and  soreness  of  the  teeth  and  swelling  of 
the  gums ;  that  is,  a  general  pericementitis  and  maxillary  periostitis 
arise.  Potassium  iodid  administered  in  this  condition  relieves  the 
maxillary  periostitis  and  pericementitis  ;  but  the  same  drug  administered 
in  health,  or  for  conditions  other  than  mercurial  ])oisoning,  also  causes 
irritation  of  the  pericementum.  Pilocarpin  has  a  similar  effect,  though 
in  much  less  degree.  All  of  these  drugs  are  partially  eliminated  by  the 
glandular  appendages  of  the  mouth,  and  during  elimination  apparently 
act  as  local  irritants. 

Patients  who  have  a  gouty  heredity,  or  who  are  the  subjects  of 
active  gout,  frequently  exhibit  a  tenderness  of  the  entire  pericementum 
of  one  or  more,  or  sometimes  all  of  the  teeth.  This  pericemental  dis- 
turbance may  be  the  precursor  of  an  acute  outbreak  of  gout  in  the 
metatarso-phalangeal  joint. 

Scurvy — a  very  rare  disease — is  attended  by  rapid  degeneration  of  the 
pericementum  of  the  teeth  and  of  the  alveolar  tissues. 

Diagnosis  and  Prognosis. — The  history  of  these  cases  is  all- 
important.  Has  an  injury  been  received,  or  is  the  patient  aware  of  the 
introduction  or  presence  of  foreign  bodies  ?  Did  the  inflammation  arise 
immediately  after  the  placing  of  a  barrel  crown  ?  A  history  of  drug- 
administration  may  be  obtained,  and  the  constitutional  state  produced 
by  drug-administration,  or  by  the  presence  of  waste-matters  in  the  circu- 
lating fluids,  may  be  evidenced  by  a  widespread  disturbance  not  having 
a  local  explanation. 

Cases  communicating  with  the  mouth-cavity  may  become  purulent, 
and  the  condition  then  becomes  acute  septic  pericementitis,  discharging 
at  the  gum-margin,  and  the  origin  of  the  condition  be  thus  obscured. 
Many  of  these  disorders  occur  about  teeth  containing  normal  pulps,  as 
may  be  shown  by  the  thermal  test. 

If  the  exciting  cause  of  the  condition  be  removable,  and  degenera- 
tive changes  be  not  too  pronounced,  complete  recovery  may  be  hoped  for. 
If  the  source  of  irritation  continue,  degeneration  of  the  ])ericementum 
usually  persists  until  the  tooth  is  lost,  hastened  by  the  infection,  which 
nearly  always  follows. 

Treatment. — The   treatment  consists  in,  first,  removing  the  cause, 


OVERUSE  OF  TEETH.  437 

whicli  the  history  of  the  case  usually  discloses ;  secondly,  procure  rest 
and  reduce  tlie  morbid  vascular  (jonditiou.  Tiic  treatment  of  trau- 
matic cases  has  already  been  discussed.  If  foreign  bodies  are  present, 
they  should  be  sought  for  and  removed.  If  the  inflammation  have 
arisen  immediately  after  adjusting  a  barrel  crown,  and  has  persisted,  a 
careful  examination  should  be  made  for  loose  particles  or  project- 
ing masses  of  hardened  cement ;  if  not  found,  the  crown  should  be 
removed,  the  inflammation  reduced,  and  a  properly  made  crown  adjusted. 
Cases  due  to  constitutional  causes  persist  as  long  as  the  general  irritant 
is  present ;  if  this  be  a  drug,  as  mercury,  its  elimination  is  hastened  by 
means  of  potassium  iodid  administered  internally,  and  the  local  symp- 
toms reduced  by  means  of  strong  solutions  of  potassium  chlorate.  If 
any  of  the  products  of  faulty  metabolism — uric  acid  and  allied  sub- 
stances— be  the  offenders,  they  should  be  gotten  rid  of  by  flushing  the 
kidneys,  using  uric-acid  soK^ents  :  lithium  salts,  piperazin,  etc.  In  any 
event,  the  pericementum  is  to  be  given  a  rest  through  means  already 
described,  and  mouth-washes  of  hamamelis,  etc.,  advised. 

CHEONIC    VARIETY. 

Causes. — Cases  of  chronic  general  aseptic  pericementitis  are  usually 
due  to  either  the  continuance  of  some  of  the  causes  which  gave  rise  to 
the  acute  variety,  or  to  overuse,  misuse,  or  disuse  of  the  teeth  ;  these 
are  termed  mal-occlusion  and  non-occlusion  of  the  teeth — either  general 
overwork,  improper  work,  or  an  absence  of  work. 

The  results  of  overuse,  disuse,  and  misuse  of  teeth  are  more  cor- 
rectly described  as  degenerations  rather  than  expressions  of  inflamma- 
tion, although  inflammation,  simple  or  infective,  may  occur  at  any  time 
in  the  histories  of  the  cases.  The  functional  abuses  comprised  in  this 
subheading,  by  inducing  degenerative  changes,  furnish  areas  of  lessened 
resistance,  points  of  determination  for  the  lighting  up  of  the  condition 
imperfectly  described  as  pyorrhoea  alveolaris.  In  still  other  cases  local- 
ized areas  of  cellular  debility  or  even  cell-necrosis  are  found,  which 
become  infected  by  pyogenic  organisms,  forming  defined  abscess  upon 
some  lateral  aspect  of  a  tooth,  the  pulp  of  the  tooth  being  alive,  and 
the  gingival  portion  of  the  pericementum  still  firmly  attached. 

Overuse  of  Teeth. 

By  overuse  of  a  tooth  is  meant  such  a  variety  of  occlusion  that  the 
tooth  receives  a  greater  stress  than  its  neighbors,  or  than  it  is  designed 
to  bear.  The  stress  may  be  received  in  the  normal  direction,  but  l>e 
excessive  in  amount.  The  most  prominent  cause  of  this  condition  is 
the  loss  of  one  or  more  other  teeth,  permitting  undue  stress  to  fall  upon 
the  neighboring  teeth,  or,  in  some  cases,  on  far  distant  teeth.     Too- 


438        NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS. 

prominent  artificial  crowns,  particularly  those  of  the  all-gold  type, 
cause  a  general  increase  of  stress  upon  the  pericementum.  Enormous 
contour-fillings  overfull  may  establish  a  similar  condition.  When  but 
few  isolated  teeth  remain  in  one  denture  and  have  antagonists,  the  teeth 
are  certain  to  be  overworked.  Isolated  and  other  teeth,  to  which  are 
attached  clasps  of  artificial  dentures,  are  in  the  majority  of  cases  being 
constantly  overstrained. 

Pathology. — Like  any  other  functional  part  which  is  overworked, 
the  pericementum  is  first  stimulated,  causing  the  vessels  to  dilate. 
Soon  evidences  of  overwork  appear  in  a  passive  dilatation  of  the  peri- 
cemental vessels,  and  atonic  hypersemia  is  established.  The  condition 
passes  into  one  of  irritation ;  the  tooth  projects,  and  is  loosened ;  the 
overlying  gum  deepens  in  color ;  and  evidences  of  venous  engorgement 
are  common.  The  result  of  the  condition  is  a  softening  and  degenera- 
tion of  the  substance  of  the  pericementum  ;  the  alveolar  wall  is  involved 
in  the  degeneration,  and  it  melts  down — disappears  to  a  greater  or  less 
extent.  At  any  stage  of  the  disturbance  infection  may  occur,  and  the 
degeneration  and  destruction  of  the  pericementum  be  hastened  by  sup- 
puration, or  other  secondary  degenerations. 

The  symptoms,  diagnosis,  and  clinical  history  are  involved  in  the 
description.  The  prognosis  is  the  inevitable  loss  of  the  tooth  if  the 
causes  be  not  removed,  in  which  event,  the  prognosis  is  governed  by 
the  extent  to  which  the  degeneration  has  proceeded. 

Treatment. — The  treatment  is  the  removal  of  the  causes  and  pro- 
curing surgical  rest  until  the  injured  pericementum  has  recovered.  The 
insertion  of  carefully  made  artificial  dentures  is  indicated  in  those  cases 
of  scattered  natural  teeth  having  spaces  between  them.  The  prosthetic 
appliance  must  not  be  attached  to  these  teeth,  nor  in  its  movements 
should  it  bear  against  them.  No  attempt  is  made,  however,  to  cause 
the  artificial  teeth  strike  before  the  natural  teeth  in  the  hope  of  giving 
surgical  rest  to  these  organs.  Such  attempts  always  result  in  failure, 
as  they  cause  injuries  to  the  tissues  upon  which  the  plate  and  teeth 
rest,  which  are  more  severe  than  the  pericemental  disturbance. 

Properly  adjusted  bridge-work  frequently  does  good  service  in  these 
cases,  provided  the  over-occluding  tooth  or  teeth  be  first  dressed  down 
short  of  occlusion  and  are  given  a  period  of  rest,  until  the  peri- 
cementum recovers.  The  bridge,  if  carefully  planned,  may  be  made  to 
direct  and  control  the  stress  received  by  the  injured  teeth. 

Improperly  occluding  artificial  crowns  should  have  this  fault  cor- 
rected, by  removing  the  excess  of  material  or  by  setting  properly  made 
crowns. 

Overfull  fillings  should  be  reduced  to  correct  proportions  and  shape. 

Teeth  which  are  being  strained  by  clasps  should  have  the  latter 


MAL-OCCLUSION  OF  THE  TEETH.  439 

removed.     If  necessary,  a  new  ap})liance  should  be  made  on  which 
clasps  are  either  omitted,  or  are  })ro})erly  designed  for  other  teeth. 
Surgical  rest  is  the  only  hope  of  saving  the  tooth. 

Mal-occlusion  op  the  Teeth. 

Each  tooth  of  a  denture  is  not  only  designed  to  receive  a  definite 
amount  of  force,  but  to  receive  it  in  a  particular  direction  or  directions  ; 
any  excess  of  this  force,  or  alteration  of  its  direction,  is  followed  by 
abnormal  stimulation  of  the  pericementum  (see  Chapter  VIII.),  and 
by  its  overstraining.  The  effects  following  a  general  increase  of  stress 
have  been  considered  under  the  previous  heading.  By  mal-occlusion 
is  here  meant,  the  constant  reception  of  stress  by  the  pericementum  in 
directions  to  which  it  is  unaccustomed,  or  are  not  in  accordance  with 
the  anatomical  design  of  the  tooth. 

Causes. — Original  malpositions  of  the  teeth  may  cause  their  faulty 
occlusion.  The  most  prolific  source  of  the  condition  is,  however,  altered 
occlusion  due  to  those  changes  of  position  of  the  teeth  which  follow  upon 
the  loss  of  adjoining  teeth. 

Artificial  crowns  which  do  not  occlude  in  correspondence  with  the 
other  teeth  are  a  common  cause.  Improperly  formed  fillings  are  another 
cause. 

The  shifting  of  positions  of  the  teeth,  in  consequence  of  pathological 
changes  occurring  in  or  about  the  pericementum,  cause  the  crowns  of 
teeth  to  occlude  improperly. 

Pathology. — The  conditions  established  are  either  those  of  overuse 
or  of  disuse.  A  typical  example  of  this  condition  is  that  of  a  lower 
second  molar  which  has  gradually  tilted  forward  in  consequence  of  the 
loss  of  the  first  molar  ;  or  a  central  incisor  which  has  altered  its  position 
in  consequence  of  secondary  formations  in  or  about  the  pericementum, 
a  common  precursor  of  phagedenic  pericementitis.  Some  portion  of 
the  tooth,  an  edge,  which  before  did  not  occlude  with  an  antagonizing 
tooth,  is  brought  into  occlusion ;  if  the  occlusion  be  not  unduly  forcible, 
no  immediate  degenerative  changes  are  evident.  If  the  occlusion  be 
excessive,  the  pericementum  is  not  uniformly  affected,  but  the  greatest 
stress  is  brought  to  bear  upon  some  lateral  aspect  of  the  structure.  It 
responds  in  the  degree  of  the  overwork,  and  degenerative  changes  occur, 
which,  if  the  active  causes  be  not  removed,  gradually  spread  to  other 
portions  of  the  pericementum,  and  the  phenomena  noted  in  connection 
Avith  overuse  occur,  but  are  not  so  general  in  distribution.  The  tooth 
becomes  more  movable  in  one  or  more  directions — /.  e,,  is  loosened ;  it 
may  develop  some  degree  of  tenderness  upon  percussion,  and  the  gum- 
color  toward  the  affected  side  deepens,  although  it  may  remain  normal 
in  other  parts.     As  in  the  previous  cases,  infection  may — indeed,  is 


440        NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS. 

likely  to — occur,  and  suppurative  processes  may  hasten  the  pericemental 
destruction.  In  some  cases  the  pericementum  may  degenerate  and  be 
destroyed  about  one  root  of  a  multirooted  tooth,  and  remain  about  the 
other. 

Diagnosis. — In  all  malposed  teeth  a  careful  examination  should  be 
made  of  their  mode  of  occlusion.  If  the  tooth  exhibit  tenderness  and 
looseness,  mal-occlusion  is  almost  a  certainty ;  it  only  remains  to  deter- 
mine its  direction. 

The  spots  of  faulty  occlusion  may  be  determined  by  placing  a  strip 
of  carbon  paper  (articulating  paper)  over  the  tips  of  the  antagonizing 
teeth  and  having  the  patient  bite  ;  the  spots  of  contact  should  then 
be  ground  away  until  the  tooth  is  slightly  short  of  direct  occlusion. 
Fresh  strips  of  paper  are  used,  and  the  jaws  moved  laterally,  as  in  mas- 
tication, to  note  other  points  of  contact ;  these  should  also  be  ground 
away.  When  several  teeth  are  affected  to  any  extent,  whether  by  a 
primary  shifting  of  position,  without  evident  vascular  symptoms,  or 
infection  have  occurred,  and  pyorrhoea  alveolaris  is  established,  it  may  be 
advisable  to  make  accurate  models  of  both  dentures,  mount  them  in  a 
Bonwill  articulator,  and  carefully  note  the  points  of  undue  contact. 
If  tin  models  be  made,  the  points  of  mal-occlusion  may  be  filed 
away  until  the  occlusion  is  normal.  The  positions  of  the  filed 
spots  on  the  models  furnish  infallible  guides  for  grinding  the  natural 
teeth. 

The  study  of  these  conditions  of  tooth-usage  should  be  made  paral- 
lel with  a  study  of  the  conditions  included  under  the  generic  title  of 
pyorrhoea  alveolaris. 

Prog-nosis. — If  the  condition  be  not  corrected  every  time  occasion 
requires,  the  degeneration  progresses  until  the  tooth  is  lost.  While 
there  are,  no  doubt,  several  other  factors  which  act  as  predisposing 
causes  of  the  ultimate  atrophy  or  necrosis  of  the  pericementum — pyor- 
rhoea alveolaris,  phagedenic  pericementitis,  and  gouty  pericementitis — 
yet  faulty,  excessive,  or  non-usage  of  the  pericementum  must  take  first 
rank  as  local  predisposing  causes. 

Treatment. — The  principle  of  treatment  is  the  removal  of  active 
causes,  implying  correction  of  the  occlusion ;  the  removal  of  dead  tis- 
sue, including  tooth-roots  which  are  entirely  denuded  of  pericementum  ; 
and  securing  a  period  of  surgical  rest.  The  correction  of  the  occlusion 
has  been  described  under  the  head  of  diagnosis.  Subsequent  correc- 
tions are  usually  required  at  intervals. 

Artificial  crowns  need  special  scrutiny  to  see  that  the  occlusal  sur- 
faces are  properly  restored. 

When  atrophy  and  death  of  portions  of  the  pericementum  have 
occurred,  conditions  are  established  which  are  described  in  subsequent 


DISUSE  OF  TEETH.  441 

chapters,  where  their  clinical  histories,  treatment,  etc.,  are  also  dis- 
cussed. 

Disuse  of  Teeth. 

Definition. — By  disuse  of  teeth  is  meant  a  degree  of  usage  less 
than  the  amount,  the  forms,  and  structure  of  the  teeth  and  contiguous 
parts  fit  them  for.  The  disuse  may  be  absolute  or  relative  ;  teeth  may 
not  occlude  at  all,  owing  to  the  loss  of  antagonists  or  to  extremely 
irregular  positions. 

PARTIAL    DISUSE. 

Causes  and  Clinical  History. — The  meaning  of  relative  disuse  needs 
exhaustive  inquiry.  Black's  ^  experiments  have  shown  that  the  strength 
of  the  muscles  of  mastication,  and  the  amount  of  stress  the  pericemen- 
tum will  bear,  differ  with  the  individual  (see  Chapter  VIII.).  One 
person  taking  a  morsel  of  food,  such  as  a  fragment  of  meat,  between 
the  teeth  may  crush  it  flat  with  one  closure  of  the  jaws  ;  another  will 
require  continued  mastication  to  reduce  it.  The  amount  of  exercise 
the  teeth  (the  pericementum)  receive  in  the  first  individual  is  much 
greater  than  with  the  second.  Moreover,  the  teeth  and  alveolar  process 
of  the  first  are  of  a  type  called  highly  organized.  If  in  either  or  any 
case,  soft  food  be  substituted  for  that  requiring  strong  mastication,  the 
functional  activity  of  the  pericementi  is  lessened  because  of  lack  of 
exercise.  Naturally  the  eflJects  are  in  the  degree  of  lessened  exercise, 
all  other  factors  being  equal ;  and  this  amount  is  relatively  least  where 
the  teeth  are  of  a  type  designed  for  hard  usage. 

Pathology  and  Morbid  Anatomy. — Lack  of  exercise  is  necessarily 
followed  by  atony  ;  and  if  it  occur  in  a  part  accustomed  to  vigorous 
exercise,  degenerative  changes  proportioned  to  the  degree  of  disuse  are 
sequelfe.  Atony,  debility,  etc.,  are  followed  by  the  less  pronounced 
degenerations,  and  result  in  atrophy.  In  all  cases,  Avhether  relative  or 
absolute  disuse,  the  bloodvessels  of  the  pericementum  share  in  the 
atony,  and  a  passive  dilatation  or  hyperemia  results  ;  lacking  in  varying 
degree  the  stimulus  derived  from  mastication  (exercise),  and  the  adjunc- 
tive circulatory  force  exerted  thereby,  the  vascular  current  becomes 
sluggish,  and  areas  of  lessened  resistance  are  formed.  The  vascular 
conditions  are  the  antecedents  of  degeneration.  The  clinical  importance 
of  the  condition  at  the  stage  described,  is  that  it  frequently  precedes 
persistent  atrophic  conditions  of  the  pericementum — i.  e.,  phagedenic 
pericementitis.  In  gouty  patients  it  establi.shes  a  weak  joint,  which 
may  be  the  point  of  deposit  of  gouty  poison.  The  gum-tissues  also 
may  become  debilitated,  owing  to  the  absence  of  their  normal  stimuli, 
and  passive  hyperaemias  result.    Other  evils  follow ;  food-debris  collects 

^  Dental  Cosmos,  1895. 


442        NON-SEPTIC  GENERAL  AND  APICAL  PERICEMENTITIS. 

in  unusual  amounts,  and  abnormal  fermentations  occur,  producing  gingi- 
vitis (whicli  see). 

Diagnosis  and  Prognosis. — A  diagnosis  of  disuse  (relative)  is 
usually  made  out  by  inquiring  as  to  the  food-habit  of  individuals.  It  is 
excessively  common  in  civilized  communities,  particularly  among  the 
well-to-do,  and  is  of  almost  constant  occurrence  in  gourmands. 

Treatment. — Patients  should  have  pointed  out  to  them  the  results 
of  insufficient  mastication,  together  with  the  evils  of  faulty  oral  hygiene. 
Every  effort  should  be  made,  by  the  use  of  antiseptic  and  mildly  astrin- 
gent mouth-washes,  to  forestall  the  common  sequel  of  these  conditions, 
progressive  degenerations  and  loss  of  the  teeth.  These  and  similar 
conditions  are  particularly  to  be  feared  in  the  degenerative  periods  of 
early  and  late  middle-age.  It  is  between  the  ages  of  thirty  and  fifty 
years  that  ill-consequences  are  most  to  be  feared  from  acquired  debility 
of  the  pericementum. 

ABSOLUTE   DISUSE. 

Definition. — Teeth  which  perform  no  work  directly  in  mastication, 
or  indirectly  by  serving  as  abutments  for  a  bridge-piece,  may  be  said  to> 
be  in  a  condition  of  absolute  disuse. 

Results. — A  tooth  or  root  whose  pericementum  receives  no  stimulus 
becomes  relatively  a  foreign  body  to  the  organism.  It  is  a  useless  part, 
and  the  body  attempts  to  cast  it  out.  Perhaps  these  phrases  are  in- 
sufficiently exact ;  however,  a  disused  tooth  is  lost  through  a  series  of 
pathological  changes.  Teeth  which  perform  no  work  may  be  retained 
in  the  mouths  of  young  children  and  young  adults  for  long  periods  with- 
out marked  changes  occurring  in  their  vital  connections,  but  during  the 
degenerative  period  of  life  they  are  usually  lost  with  a  degree  of  rapidity 
differing  in  individuals. 

The  pericemental  condition  of  passive  hyperseraia  following  upon 
relative  disuse  of  the  teeth  has  been  described  ;  the  condition  following 
upon  absolute  disuse  differs  in  that  the  pericementum  receives  no  exer- 
cise whatever.  The  clinical  history  of  these  cases  is  that  of  a  progressive 
extrusion  of  the  tooth  ;  it  projects  beyond  its  fellows  in  increasing  degree. 
The  borders  of  the  alveolar  process  recede,  but  usually  to  less  extent 
than  the  tooth  protrudes  or  is  extruded.  The  tooth  becomes  progres- 
sively looser,  until  in  its  latest  stages  a  portion,  which  may  be  one-half 
of  its  root-length,  is  attached  to  the  jaw  through  the  medium  of  a  mass 
of  soft  tissue  alone  ;  all  true  alveolar  connection  has  disappeared.  After 
extraction  or  complete  extrusion,  the  root  of  the  tooth  is  seen  to  be 
devoid  of  pericementum  except  at  the  apex  of  the  root.  The  alveolar 
process  has  undergone  limited  atrophy,  although  in  some  cases  its 
outer  walls  may  be  thickened. 


DISUSE  OF  TEETH.  443 

Patholog-y. — The  passive  hyperemia  has  apparently  led  to  swelling 
and  degeneration,  with  snbseqnent  atrophy  of  the  perieementum,  and  the 
normal  atrophic  ehanges  whieh  occnr  in  the  alveolar  process  have 
become  hastened  and  qnickened.  These  cases  frequently  become  com- 
plicated by  infections,  when  the  tooth-loosening  becomes  pronounced. 
The  pulp-vessels  are  cut  off  and  the  dead  pulp-tissue  furnishes  a  soil  for 
micro-organisms,  whose  poisons  hasten  degeneration  of  the  tissues  in 
the  abnormal  alveolus.  Suppuration  may  occur — /.  e.,  abscess  form. 
Through  this  process  the  jaws  cast  out  crownless  roots  ;  in  these  the 
local  alveolar  atrophy  may  be  complete  before  there  is  external  evidence 
of  it.  The  danger  of  infection  is  always  great  in  these  cases.  Some 
degree  of  infection,  no  doubt,  exists  in  all  of  them,  which  serves  to 
explain  the  increased  rapidity  of  the  degenerations. 

Prognosis. — If  teeth  can  be  directly  or  indirectly  brought  into  use, 
so  that  their  pericementi  receive  exercise,  the  cases  may  recover,  pro- 
vided the  atrophic  changes  are  not  very  pronounced ;  in  which  event 
the  atrophy  proceeds,  although  more  slowly.  Teeth  crowned  or  made 
abutments  for  bridges,  after  degenerative  chauges  have  become  estab- 
lished— /.  e.,  when  the  normal  pericementum  has  been  replaced  by 
a  thickened  mass  of  partially  organized  connective  tissue — usually  be- 
come progressively  looser ;  the  alveolar  atrophy  proceeds  until  all 
attachment  is  lost.  Utilized  early,  the  teeth  may  be  saved.  The 
results  are  better  if  the  teeth  or  roots  be  utilized  before  the  age  of 
thirty  than  at  later  ages. 

Treatment. — The  treatment,  as  might  be  inferred  from  the  foregoing 
statements,  consists  in  bringing  the  teeth  into  use,  if  the  degeneration 
have  not  proceeded  too  far.  Later,  extraction  is  inevitable.  The  opera- 
tion, when  determined  upon,  should  not  be  delayed,  for  not  only  are 
bacterial  growths  invited  about  the  loosened  tooth,  but  the  soft  tissues 
are  frequently  increased  in  volume,  if  extraction  be  delayed  until 
complete  local  atrophy  of  the  alveolar  walls  has  taken  place,  a  soft  and 
spongy  mass  remains,  which  interferes  with  the  comfortable  wearing  of 
prosthetic  appliances  in  the  future. 


CHAPTER    XXIV. 

PERICEMENTAL  DISEASES  BEGINNING  AT  THE  GUM- 
MARGIN. 

Nearly  all  the  degenerations  of  the  pericementum  which  begin 
at  the  gum-margin  are  sooner  or  later  accompanied  by  suppura- 
tive processes,  which  give  a  generic  name  to  these  conditions,  viz., 
pyorrhoea  alveolaris.  Under  this  head  dental  writers  have  included 
several  disease-processes  which  should  be  clearly  differentiated  from 
one  another.  In  general  terms,  these  diseases  are  characterized  by  an 
inflammation  origiDating  about  the  gum -margin,  and  followed  by  a 
jjrogressive  degeneration  and  atrophy  of  the  pericementum  and  of  the 
alveolar  walls.  In  the  areas  of  pericemental  atrophy  and  death,  progres- 
sive deposits  of  calculi  take  place,  and  infection  of  the  disease-territory 
by  pyogenic  organisms  is  the  rule.  Their  characteristics,  therefore,  are 
loss  of  pericementum  in  any  direction,  forming  pockets  in  which  calculi 
deposit,  and  from  which  pus  exudes  or  may  be  pressed.  The  primary 
cause  of  the  atrophy,  pericemental  necrosis,  calculi,  and  infection  are 
so  clearly  associated  with  a  primary  affection  of  the  gums  about  the 
necks  of  the  teeth,  that  a  critical  examination  of  the  causes,  clinical 
history,  and  pathology  of  inflammation  of  the  gum-margin  is  a  neces- 
sary preliminary  to  the  study  of  the  later  degenerations. 

Gingivitis. 

Definition. — The  term  gingivitis,  as  at  present  understood,  applies 
to  an  inflammation  confined  to  the  margins  of  the  gum  about  the  necks 
of  the  teeth,  in  contradistinction  to  general  inflammation  of  the  gums, 
called  ulitis.  Fault  may  be  found  with  this  distinction  as  not  being 
warranted  by  etymology  or  dictionary  definitions,  so  that  perhaps  "  mar- 
ginal gingivitis  "  would  be  a  more  correct  term. 

The  causes  of  marginal  gingivitis  are  local  and  general,  which  may 
be  subdivided  into  predisposing  and  exciting.  Any  conditions,  general 
or  local,  which  reduce  the  vitality  of  the  tissues  forming  the  gum-mar- 
gins Avill  cause  a  predisposition  to  local  disease,  when  exciting  causes 
may  become  operative  which  before  were  inoperative.  It  is  still  an 
open  question  whether  this  is  the  mode  of  action  of  what  are  known 
as  the  general  or  constitutional  causes  of  marginal  gingivitis.  Be  this 
as  it  may — and  it  is  an  important  question — marginal  gingivitis  is  an 

444 


GINGIVITIS.  445 

associate  of  several  general  disease-states  and  conditions  of  faulty  metab- 
olism. Rhein  ^  found  after  repeated  examinations  of  hospital  patients  that 
"  marginal  gingivitis  was  an  accompaniment  of  typhoid  fever,  tuberculo- 
sis, malarial  disorders,  acute  rheumatism,  pleurisy,  pericarditis,  and  syph- 
ilis, among  the  acute  diseases.  Of  chronic  nutritional  diseases,  it  was 
commonly  observed  in  cases  of  gout,  diabetes,  chronic  rheumatism, 
several  forms  of  nephritis,  scurvy,  chlorosis,  anaemia,  leuksemia,  and 
pregnancy.  Also  in  disorders  of  the  central  nervous  system  and  fol- 
lowing the  administration  of  mercury,  lead,  and  iodin." 

In  some  of  these  disorders,  notably  typhoid  fever  and  other  acute 
diseases,  diabetes,  pregnancy,  and  disorders  of  the  nervous  system,  local 
causes  are  sufficient  to  account  for  the  gingivitis,  and  may  completely 
mask  connection  with  the  constitutional  causes.  The  connection  with 
gout  and  other  arthritic  diseases,  Bright's  disease,  anaemic  disorders, 
and  tuberculosis  is  clear  and  undoubted.  Rhein  states  that  the  S'inm- 
vitis  produced  by  any  of  the  causes  named  has  distinctive  features 
which  may  even  serve  as  diagnostic  signs  of  the  nature  of  the  general 
malady.  To  render  the  problem  less  complex,  and  discover  more  gen- 
eral causes,  the  nature  of  the  tissue-changes  induced  by  these  diseases 
must  be  examined.  Most  of  them,  it  will  be  observed,  may  be  classified 
as  diseases  of  suboxidation ;  diseases  in  which  the  oxidizing  element 
of  the  body — haemoglobin — is  in  reduced  amount ;  where  products  of 
insufficient  oxidation  are  formed  or  retained,  and  where  probably  faulty 
oxidation  is  the  result  of  cell-disorders ;  oxygen  in  insufficient  amount ; 
cells  unable  to  oxidize  and  deoxidize ;  oxidizable  material  in  undue 
amount  or  of  imperfect  character  ;  and,  lastly,  a  retention  of  waste-prod- 
ucts of  tissue-  and  perhaps  of  food-metabolism  in  the  circulating  fluids. 
As  in  all  nutritional  disturbances,  degenerative  disorders  most  affect 
parts  peripheral  to  the  circulation — the  parts  become  debilitated. 

The  local  causes  of  gingivitis,  some  of  them  probably  necessary  in 
all  cases  to  the  occurrence  of  the  disorder,  are  more  tangible.  The  local 
causes  may  be  divided  into  predisposing  and  exciting. 

The  local  predisposing  causes  are  lack  of  exercise,  the  gums  not  re- 
ceiving the  usual  friction  and  buffeting  by  food-masses  during  mastica- 
tion, and  permitting  the  food-masses  to  remain  in  contact  with  the  gums, 
where  the  products  of  their  decomposition  act  as  irritants.  The  local 
exciting  causes  are  both  mechanical  and  chemical,  and  act  vigorously 
in  the  degree  that  local  and  general  predisposing  causes  ex:ist. 

The  mechanical  causes  are  the  presence  of  foreign  bodies,  such  as 
deposits  of  salivary  calculi  resting  upon  the  gum  or  beneath  the  gum- 
margin  ;  fillings  projecting  beyond  cavity-margins ;  gum  overhanging 
cavity-margins ;    projecting    edges   of    artificial    crowns ;    tooth-brush 

1  Dental  Cosmos,  1894. 


446     PERICEMENTAL  DISEASES  BEGINNING  AT  THE  GUM-MABGIN. 

bristles  ;  fragments  of  bone  tooth-picks  ;  improper  contact  of  the  edges 
of  prosthetic  plates  or  appliances  about  the  necks  of  the  teeth ;  injuries 
inflicted  by  rubber-dam  clamps,  ligatures,  wedges,  etc. 

The  chemical  causes  are  the  presence  in  the  gum-tissue  of  irritant 
drugs,  probably  in  process  of  elimination — lead,  mercury,  iodids  ;  the 
contact  of  caustics  applied  in  the  treatment  of  other  dental  diseases, 
and  chemical  poisons  generated  through  the  action  of  mouth  bacteria. 
The  latter  cause  probably  complicates  all  the  others. 

Symptoms. — The  symptoms  depend  upon  the  cause.  Swelling  and 
increased  redness  of  the  gum-margins  are  constant  features.  In  gin- 
givitis due  to  any  of  the  constitutional  causes  named,  the  aifection  is 
general,  but  the  symptoms  are  more  marked  in  some  diseases  than  others 
and  usually  are  pronounced  in  proportion  to  the  neglect  of  oral  hygiene. 
In  some  cases  there  may  be  only  a  raised,  rounded,  softened  ridge  of 
gum,  of  a  bright  red  color;  but  in  other  cases,  the  swollen  gum  may 
obscure  fully  one-half  of  the  tooth-crown,  and  the  softened  tissue  be 
purplish  in  color. 

Prognosis. — The  prognosis  of  marginal  gingivitis  is  governed  by  its 
causes,  the  length  of  time  they  have  been  in  operation,  and  the  age  of 
the  patient.  Gingivitis  commencing  at  the  degenerative  period  of  life, 
particularly  when  conditions  exist  which  lessen  the  normal  resistive 
power  of  the  pericementum,  is  certain  to  establish  degenerative  changes 
in  the  latter  structure.  Degenerative  and  atrophic  changes  of  the  peri- 
cementum and  alveolar  walls  are  inevitable  in  long-continued  gingivitis. 

If  the  trouble  be  purely  local — that  is,  due  to  local  causes  alone — it 
usually  subsides  promptly  upon  the  removal  of  the  cause.  The  peri- 
cemental and  alveolar  atrophy  which  has  occurred  makes,  however,  a 
permanent  loss,  so  that  when  recovery  occurs,  the  gum-line  is  seen  to 
have  receded  beyond  its  normal  line  of  attachment  to  the  teeth. 

Treatment. — The  treatment  of  the  condition  consists  in  removing 
the  source  of  irritation  and  restoring  the  normal  circulation  in  the 
parts.  If  the  source  of  the  disorder  be  in  some  underlying  constitu- 
tional condition,  the  symptoms  may  be  ameliorated,  although  not 
entirely  cured,  by  the  correction  of  the  general  disorder. 

Cases  due  to  mechanical  irritation  are  commonly  confined  to  one  or 
several  teeth,  rarely  to  an  entire  denture,  except  cases  continued  in  con- 
sequence of  deposits  of  scaly  calculi  beneath  the  gum-margin.  Foreign 
bodias,  such  as  bristles  and  fragments  of  bone,  should  be  removed. 
Projecting  fillings  or  overhanging  crown-margins  should  be  made 
flush  with  the  general  tooth-surface.  Salivary  calculi  should  be  re- 
moved. 

Antiseptic  mouth- washes  should  be  employed  frequently,  no  matter 
what  the  cause.     If  the  gum -tissue  be  soft  and  spongy,  showing  signs 


SALIVARY  CALCULUS.  447 

of  venous  hypersemia,  antiseptic,  astringent  mouth-washes  should  be 
freely  used. 

I^.  Zinc,  chlorid,  gr.  x  ; 

Aq.  nienth.  pip.,  Sj. — M. 

used  in  spray  from  an  atomizer  or  as  a  wash  several  times  a  day  is  an 
excellent  local  application,  meeting  both  indications.  Preparations  con- 
taining carbolic  acid  and  allied  substances  do  not  appear  to  act  happily  in 
these  cases.  Prescriptions  containing  eucalyptus  and  benzoic  acid  are  to 
be  preferred  : 

^.  Acid,  benzoic,  3  parts  ; 

Tr.  eucalypti,  15     " 

01.  menth.  pip.,  1  part ; 

Alcohol,  100  parts ; 
Saccharin,  2     "     — M.  (Miller.) 

The  above  formula  diluted  one-half  is  agreeable  and  efficient. 

Listerine,  borine,  borolyptol,  and  other  preparations  of  thymol,  boric 
acid,  eucalyptus,  etc.,  are  all  useful  when  conjoined  with  the  removal 
of  every  local  and  general  cause  discoverable. 

Specific  local  causes  of  gingivitis,  such  as  salivary  calculi,  require 
special  consideration. 

Salivary  Calculus. 

Salivary  calculi  are  hard  formations  composed  of  the  calcium  salts 
of  the  saliva  which  have  been  deposited  or  precipitated,  and  combined 
in  an  unknown  manner  with  organic  substances,  usually  mucin. 

Occurrence. — They  are  found  upon  the  surfaces  of  the  teeth,  notably 
in  situations  opposite  the  mouths  of  the  salivary  glands ;  in  the  ducts 
of  the  muciparous  salivary  glands  (sublingual  and  submaxillary),  and 
beneath  the  margins  of  the  gums. 

Varieties. — Clinically  three  varieties  of  salivary  calculi  are  recog- 
nizable :  first,  the  soft,  friable,  whitish-yellow  deposits  found  u|)on  the 
buccal  surfaces  of  the  upper  molars  and  upon  the  lingual  surfaces  of 
the  lower  anterior  teeth  ;  second,  dark-colored  and  hard  deposits  found 
more  frequently  in  the  latter  situation,  less  frequently  in  the  former  ; 
third,  dark,  hard,  scaly  deposits  found  first  immediately  beneath  the 
gum-margin  and  extending  from  that  point.  Deposits  u])on  tlie  teeth 
have  been  divided  into  salivary  and  sanguinary  or  serumal,  j)tyalogenic 
and  hsematogenic  calculi  (Peirce),  and  the  scaly  deposits  named  have  by 
some  writers  been  classified  as  hematogenic  or  serumal,  which  is  incor- 
rect ;  as  stated  by  Peirce,  their  origin  is  ptyalogenic,  not  haematogenic. 


448     PERICEMENTAL  DISEASES  BEGINNING  AT  THE  GUM-MABGIN. 

Serumal  calculi  are  of  two  varieties,  and  of  difFerent  origin  from  the 
ptyalogenic  calculi. 

Causes. — The  causes  of  deposits  of  salivary  calculi  are  local  and,  in 
some  cases  at  least,  general.  The  causes  will  be  more  evident  after  a 
study  of  the  conditions  under  which  the  saliva  deposits  its  calcium  salts. 

The  secretion  of  the  parotid  gland  is  more  watery  than  that  of  the 
sublingual  and  submaxillary  glands  ;  it  contains  a  globulin  but  no  mucin, 
and  contains  calcium  carbonate,  calcium  phosphate  being  present  in  but 
minute  amount.^  It  contains  sufficient  carbon  dioxid  to  hold  the  cal- 
cium salts  in  solution.  The  secretions  of  the  submaxillary  and  sub- 
lingual glands  contain  calcium  carbonate  and  calcium  phosphate  in 
nearly  equal  amounts  and  are  rich  in  mucin ;  that  of  the  sublingual 
gland  contains  the  highest  percentage  of  solids,  particularly  of  mucin. 
The  mucous  glands  of  the  mouth  have  a  viscid  secretion  (mucin)  and 
contain  some  20  parts  per  thousand  of  solids,  organic  and  inorganic 
(Jacobowitsch).  It  is,  therefore,  thicker  than  the  salivary  secretion 
proper.  The  combined  secretion,  as  found  in  the  mouth  in  conditions 
of  health,  is  a  transparent,  slimy  fluid  of  alkaline  reaction,  containing 
epithelial  (salivary)  cells,  and  from  which  carbonic  anhydrid  may  be 
jDumped  ;  sufficient  carbonic  anhydrid  is  present  to  hold  the  calcium 
salts  in  solution.  As  soon  as  the  fluid  is  exposed,  at  rest,  in  a  vessel, 
the  carbonic  anhydrid  escapes,  and  the  calcium  salts,  being  no  longer 
held  in  solution,  are  precipitated,  the  saliva  becoming  cloudy. 

In  perhaps  a  majority  of  human  mouths,  certainly  in  the  great 
majority  of  those  tested  by  dental  observers,  the  saliva  has  an  acid 
reaction.  Fermentation,  particularly  lactic  fermentation,  is  so  com- 
mon in  the  human  mouth  as  to  be  almost  a  characteristic.  It  is  due, 
no  doubt,  to  the  addition  of  the  product  of  this  fermentation,  lactic 
acid,  to  the  general  saliva  that  the  fluid  acquires  an  acid  reaction. 
Similar  conditions  are  established  in  the  mouths  of  animals  fed  upon 
cooked  starchy  foods  ;  carnivorous  and  herbivorous  animals  are  affected, 
both  domestic,  and  wild  animals  in  captivity.  It  has  been  observed  that 
mineral  acids,  and  among  the  organic  acids  acetic  acid,  have  the  power 
of  precipitating  the  mucin.  Lactic  acid  has  a  similar  property,^  exhib- 
iting particular  features.  If  to  a  test-tube  half-filled  with  saliva,  a  few 
drops  or  more  of  a  1  per  cent,  solution  of  lactic  acid  be  added,  a  cloudi- 
ness will  appear  in  the  solution  ;  shred-like  coagula  of  mucin  are  formed 
which  slowly  agglomerate  and  rise  to  the  surface  of  the  solution.  If 
the  amount  of  acid  be  increased,  the  coagula  form  more  promptly 
and  agglomerate  quickly  in  a  distinct  mass  at  or  just  beneath  the  sur- 
face of  the  solution.      If  the  coagulum  be  removed  and  dried,  it  is 

^  Halliburton,  Chemical,  Physiology  and  Pathology,  after  Mitscherlich. 
^  Burchard,  Dental  Cosmos,  1895. 


SALIVARY  CALCULUS. 


449 


Fig.  335. 


found  upon  analysis  to  contain  calcium  salts.  The  conditions  of  the  for- 
mation have  been,  therefore,  a  volume  of  saliva  in  quiescence  becoming 
acidulated  ;  throughout  the  solution  mucin  is  being  coagulated,  and  at 
the  same  time  calcium  salts  are  being  thrown  down  in  consequence  of 
the  escape  of  their  solvent,  carbon  dioxid.  These  salts  are  entangled 
in  the  mucin-coagulum  as  it  agglomerates  and  rises  to  the  surface.  The 
dried  coagula  slowly  change  color,  acquiring  a  greenish-brown  hue. 
Kirk '  believes  that  the  connection  between  the  calcium  salts  and  the 
organic  substance  to  be  more  intimate  than  a  mere  cementing  together 
of  the  calcium  particles.  Conditions  exist  somewhat  analogous  to 
those  under  which  calco-globulin  forms,  and  he  advances  the  suggestion 
that  salivary  calculi  may  have  a  family  resemblance  to  calco-globulin. 
To  brinsj  about  these  conditions  it  is  not  necessarv  that  mucin  should 
undergo  coagulation,  its  inspissation  is  alone  sufficient ;  but  some  ex- 
planation is  required  of  the  reasons 
why  calculi  are  found  in  selective 
situations. 

The  human  mouth  may  be  divided 
into  two  cavities,  a  buccal  and  a 
lingual  ;  so  far  as  the  accumulation 
of  saliva  is  concerned,  the  recep- 
tacles form  but  parts  of  each  of 
these  two  cavities.  A  lingual  cavity, 
bounded  laterally  by  the  lower  alve- 
olar walls,  beneath  by  the  floor  of 
the  mouth,  above  and  behind  by  the 
tongue,  is  that  into  which  the  sub- 
maxillary, sublingual,  and  numer- 
ous mucous  glands  discharge  their 
secretions  (Fig.  336).  A  cavity 
bounded  internally  by  the  buccal 
alveolar  wall  and  buccal  surfaces 
of  the  upper  molars,  externally  by 
the  cheek,  above  by  the  junction 
of  cheek  and  gum,  below  by  the 
edges  of  the  teeth  and  cheek,  is 
that    into    which    the    secretion    of 

the  parotid  gland  is  poured  (Fig.  335).  When  the  muscular  appendages 
of  the  mouth,  tongue,  cheeks,  and  lips,  are  at  rest  these  cavities  become 
filled  with  saliva.  The  almost  constant  muscular  movements  of  the 
structures  named  keep  the  fluids  in  a  constant  state  of  agitation;  the 
agitation,  flow  and  interchange  of  fluids  are  much  increased  by  active 

^  Dental  Cosmos,  1895. 
29 


A,  maxillary  sinus ;   B,  duct  of  Steno :  C, 
parotid  calculus  ;  E,  submaxillary  gland. 


450    PERICEMENTAL  DISEASES  BEGINNING  AT  THE  GUM-MABGIN. 

mastication.  Establish  now  a  condition  of  quiescence,  increase  the  secre- 
tion of  mucus  by  irritating  mucous  glands,  increase  also  fermentations, 
and  new  relations  are  established.  The  close  sympathetic  association  of 
the  branches  of  the  trigeminus  must  be  borne  in  mind  ;  irritation  of  the 


S.LG.L 
C,  calculus ;  S.  L.  C,  sublingual  cavity;  S.  L.  G.  L.,  sublingual  gland. 

mucous  surfaces  of  the  mouth  is  followed  by  increased  glandular 
activity,  irritation  of  exposed  dentin,  or  of  an  acutely  diseased  pulp, 
is  followed  by  increased  glandular  activity,  and  if  the  irritation  be 
prolonged,  the  character  of  the  secretion  is  altered. 

The   increase,    or   establishment,    of  these   conditions   is   found   in 
xion-mastication ;  if  one  or  more  teeth,  especially  upper  molars,  be  in 

Fig.  337. 


Right  side,  abrasion  from  over-use ;  left  side,  deposits  due  to  stagnation. 

continuous  disuse,  it  is  usual  to  find  accumulations  of  calculi  upon  them 
(Fig.  337).     If  catarrhal  conditions  of  the  mouth  (increased  mucous 


SALIVARY  CALCULUS.  451 

secretions)  occur  aud  persist  for  long  periods,  calculi  are  almost  certain 
to  form.  As  these  cases  are  commonly  associated  with  active  oral  fer- 
mentations, an  increased  production  of  acid  occurs. 

The  general  composition  of  calculi  is  usually  given ^  as  "calcium 
phosphate  and  carbonate  admixed  with  mucus  and  leptothrix."  The 
secretion  of  the  parotid  gland,  containing  but  a  trace  of  calcium  phos- 
phate with  its  calcium  carbonate,  gives  rise  to  calculi  having  a  corre- 
sponding composition  ;  in  the  calculi  upon  the  buccal  faces  of  upper 
molars  calcium  carbonate  predominates. 

Formation. — Each  of  the  three  varieties  of  salivary  calculi  exhibits 
different  conditions  of  formation.  It  is  common,  however,  to  find  two 
varieties  combined — /.  c,  the  conditions  of  formation  have  been  added 
to  one  another. 

The  typical  parotid  calculus  is  soft,  friable,  and  whitish-yellow, 
acquiring  density  with  age.  The  conditions  under  which  this  variety 
forms  appear  to  be  more  or  less  disuse  of  the  teeth  of  that  side.  This 
is  well  illustrated  in  Fig.  337.  Owing  to  the  loss  of  the  antagonizing 
teeth  of  one  side,  the  upper  posterior  teeth  of  the  same  side  have  fallen 
into  disuse  :  on  the  opposite  side  the  teeth  have  all  been  worn  down 
by  mechanical  abrasion.  The  disused  teeth  are  heavily  encrusted  with 
the  yellowish  friable  variety  of  calculi.  The  deposit  itself  probably 
occurs  as  follows  :  more  or  less  disorder  of  the  gum-structures  follows 
upon  lack  of  mastication — /.  c,  the  mucous  discharge  is  increased  ;  in  the 
buccal  cavity  (Fig.  335)  an  accumulation  of  parotid  saliva  in  a  state  of 
comparative  quiescence  takes  place  ;  the  gaseous  carbon  dioxid  escapes 
and  the  calcium  carbonate  is  precipitated ;  combining  with  any  adhesive 
matter  which  may  be  present,  notably  the  diluted  mucous  secretion 
of  the  local  glands,  collections  are  formed  which  lodge  in  the  interprox- 
imal spaces  and  in  the  small  groove  between  the  gum  and  tooth.  Suc- 
cessive portions  of  a  like  character  are  formed  and  are  added  to  the 
original  deposit. 

The  second  variety  of  calculus,  that  which  deposits  first  upon  the 
linguo-cervical  portions  of  the  lower  anterior  teeth,  and  subsequently 
between  the  teeth  and  at  the  cervico-labial  portions,  contains  a  greater 
amount  of  calcium  phosphate  and  mucin.  The  light  mucous  coagula 
found  in  the  lingual  cavity  rise  to  the  surfiice  of  the  saliva  contained 
in  this  cavity,  and  come  to  rest  at  the  cervico-lingual  borders  of  the  lower 
incisors  ;  the  pressure  of  the  tongue,  as  may  readily  be  tested,  tends 
to  drive  the  coagula  or  inspissated  mucus,  wliich  entangle  the  pre- 
cipitated calcium  salts,  between  the  teeth,  moulding  them  closely  about 
their  necks.  Subsequent  depositions  and  precipitations  occur,  which 
cause  accretions  to  the  first  deposits.  AVhen  catarrhal  gingivitis  is 
^  Vergue,  Du  tartare  dentaire  et  de  ses  concretions,  These,  Paris,  1869. 


452     PERICEMENTAL  DISEASES  BEGINNING  AT  THE  GTJM-MARGIN. 

lighted  up  from  any  cause,  and  it  is  an  inevitable  result  of  the  presence 
of  these  foreign  deposits  in  contact  with  the  gum,  it  is  seen  that  the 
calculi  change  their  physical  characteristics. 

The  calculi  deposited  in  the  regions  of  the  gingivitis  are  harder,  less 
in  amount,  and  usually  dark  green  in  color.  They  usually  intrude 
beyond  the  gum-margin.  The  swelling  incident  to  the  gingivitis  causes 
the  formation  of  a  V-shaped  depression  between  the  swollen  gum-edge 
and  the  surface  of  the  tooth.  It  is  in  these  pockets  that  the  hard,  green, 
closely  adherent  deposits  occur.  Similar  deposits  may  be  noted  beneath 
the  vellow  and  softer  calculi,  and  if  sections  of  extensive  calculi  be 
made,  these  greenish  deposits  may  be  seen  scattered  through  the  mass. 
The  greenish  deposits,  when  they  occur  alone,  are  usually  in  the  form 

of  very  hard  scales,  closely  adherent 
to  the  necks  of  the  teeth  and  lying 
within  the  free  gum-margin. 

Sections  of  extensive  calculi  show 
them  to  be  made  up  of  concentric 
layers  (Fig.  338).  Foreign  bodies 
are  sometimes  entangled  in  the  mass. 
In  some  cases  extensive  salivary  de- 
posits are  found  associated  with  highly 

A,  nidus ;  B,  calculus.  nc        •  ^  -xi         j.i     • 

oiiensive  odors  ;  either  their  presence, 
or  the  conditions  under  which  they  are  formed,  appear  to  invite  putre- 
factive decomposition  in  the  mouth.  In  the  mouths  of  smokers  deposits 
of  carbon  are  formed  upon  calculi,  giving  them  a  jet-black  surface. 

Patholog-ical  Effects  of  Calculi. — The  effects  of  deposits  of  salivary 
calculi  are  immediate  and  secondary,  and  their  nature  is  governed  largely 
by  the  character  of  the  deposits  and  by  the  existence  or  non-existence 
of  predispositions  to  pericemental  degenerations.  In  some  forms  they 
establish  immediate  predispositions  to  these  degenerations.  Their  purely 
local  significance  and  effects  must  first  be  considered. 

In  contact  with  the  mucous  membrane,  a  salivary  calculus  acts  as  a 
local  mechanical  irritant  and  excites  the  reaction  noted  in  connection 
with  other  local  irritants ;  the  form,  consistency,  composition,  and 
smoothness,  however,  represent  a  milder  type  of  irritant,  and  naturally 
their  presence  is  not  causative  of  pronounced  inflammatory  reaction. 

Figs.  339,  340,  341,  and  342,  represent  the  relations  of  deposits  of 
the  larger,  yellow  deposits  of  calculus  upon  the  loAver  anterior  teeth  and 
upper  molars.  It  is  seen  that  these  deposits  rest  on  the  gum,  and  do  not 
insinuate  themselves  between  gum  and  tooth  in  such  a  manner  as  to  sever 
their  attachment.  They  excite  hyperemia  of  the  gum  underlying  them, 
and  resorption  of  the  alveolar  walls  occurs,  beginning  at  the  margin  ; 
the  pericementum  and  alveolar  periosteum  recede  with  the  shrinking 


SALIVARY  CALCULUS. 


453 


alveolar  wall,  gradually  lessening  the  attachment  of  the  tooth.     Succes- 
sive deposits  of  calculi  occur,  which  encroach  upon  the  denuded  tooth- 


FiG.  339. 


^-O 


,-n¥kA 


Fig.  340. 


Section  of  a  lower  incisor,  with  a  large  deposit 
of  salivary  calculus  impinging  upon  and 
causing  inflammation  of  the  gum.  (Black.) 


Section  of  an  upper  molar,  with  deposit  of  cal- 
culus on  its  buccal  surface,  causing  inflam- 
mation and  absorption  of  the  gum  and 
lower  border  of  the  predental  membrane 
and  alveolar  wall.    (Black.) 


root.     The  process  is  a  gradually  progressive  one,  i3ut  the  rapidity  of 
deposit  and  of  alveolar  recession  varies  widely.    From  beginning  deposit 


Fig.  341. 


Fig.  342. 


Sectional  illustration  of  a  heavy  deposit  of 
salivary  calculus  on  a  lower  incisor,  with 
partial  destruction  of  the  alveolus  of  the 
tooth.    (Black.) 


Sectional  illustration  of  lower  incisor  with  de- 
posit of  salivary  calculus  less  heavy  than 
that  shown  in  Fig.  339.  but  with  greater 
destruction  of  the  alveolus.    (Black.) 


to  almost  complete  loss  of  alveolar  walls  may  occupy  but  a  year  or  two  ; 
in  other  cases  the  atrophy  of  the  alveolar  walls  is  very  slow.  Infection 
of  the  pericementum  may  occur,  when  the  loss  of  the  tooth  is  much 
hastened. 


454    PERICEMENTAL  DISEASES  BEGINNING  AT  THE  GUM-MARGIN. 

The  teeth  become  progressively  looser  until  all  bony  connection 
is  lost,  being  retained  at  the  apex  of  the  root  by  but  few  fibrous 
shreds.  As  soon  as  the  alveolar  loss  is  sufficient  to  cause  marked 
loosening  of  the  tooth,  infection  of  the  pericementum  is  common,  and 
suppuration  is  grafted  upon  the  results  of  mechanical  irritation. 

Prog-nosis. — The  prognosis  of  this  condition  depends  upon  the  extent 
of  alveolar  atrophy.  If  the  loss  of  support  be  not  so  extensive  as  to 
cause  marked  loosening  of  the  tooth  or  teeth,  the  teeth  may  be  retained 
for  an  indefinite  period,  if  they  be  so  attached  to  neighboring  teeth  as  to 
render  them  firm.  If  left  unsupported,  the  pericementum  is  certain  to 
degenerate,  owing  to  the  increased  mobility.  The  alveolar  atrophy  will 
continue,  and  probably  infection  of  the  degenerated  pericementum  occur. 
Redeposit  is  almost  certain  unless  all  morbid  conditions  are  removed 
and  extraordinary  precautions  be  taken  as  regards  cleanliness. 

Treatment. — The  treatment  may  be  divided  under  three  heads : 
removal  of  deposits,  correction  of  the  effects  of  their  presence,  and  pre- 
vention of  their  recurrence.  The  sole  means  of  removing  calculi  should 
be  instrumental.  It  is  frequently  recommended  that  mineral  or  some 
of  the  organic  acids  be  used  to  soften  the  deposits  to  facilitate  their 

Fig.  343. 


Scalers. 


removal.  Anyone,  having  seen  a  case  in  which  a  solution  (5  per  cent.) 
of  sulfuric  acid  had  been  used  for  this  purpose,  needs  no  further  warn- 
ing against  the  application.  Acid  solutions  will  certainly  soften  the 
deposits,  but  at  the  same  time  inevitably  cause  a  roughening  of  the 
enamel  of  the  teeth  by  a  solution  of  the  calcium  salts.     To  be  sure,  the 

Fig.  344. 


acid  does  aff'ect  the  calculus  more  than  it  affects  the  enamel,  but  the 
roughened  surfaces  of  the  latter  not  only  invite  widespread  deposits  of 


SALIVARY  CA LCUL US. 


455 


fermentable  material,  but  render  certain  tlie  more  extensive  accumula- 
tions of  calculi  in  the  future.  The  gross  deposits  may  be  removed  by 
means  of  large  sickle-shaped  scales  and  curved  chisels,  nearly  all  used 
witli  a  draw  cut  (Fig.  343).  The  instruments  should  have  sharp  edges  and 
be  introduced  beneath  the  deposits,  so  that  the  gum  is  not  unnecessarily 
wounded.  The  scaling  should  be  continued  until  every  surface  which 
can  be  cleansed  by  these  instruments  is  perfectly  smooth.  The  case  may 
then  be  dismissed  for  two  days  or  longer  ;  in  the  mean  time  an  astringent 


Fig.  345. 


Fig.  346. 


Fig.  347. 


mouth-wash  is  to  be  freely  used. 
The  zinc-chlorid  prescription  (given 
on  p.  447)  answers  admirably,  or  a 
mixture  of  equal  parts  of  listerine 
and  extract  of  hamamelis,  diluted  one-half  with  water,  is  serviceable. 
The  passive  congestion  of  the  gums  will  be  reduced  and  swelling  lessened 
by  these  washes,  permitting  a  better  view  of  the  surfaces  of  the  teeth. 
More  slender  instruments  of  chisel -form  which  will  pass  into  the  spaces 
between  the  teeth  and  beneath  the  gum-margin,  without  wounding, 
are  now  required  (Fig.  352).  All  of  the  calculi  visible,  and  all  that 
can  be  detected  by  their  roughness,  are  thoroughly  detached  and 
scraped  away  by  these  instruments.  The  surfaces  of  the  teeth  are  next 
cleansed  with  pumice  made  into  a  paste  with  glycerin.  The  paste 
is  applied  to  the  surfaces  of  the  teeth,  and  the  rubber  cups  and 
small  brushes  are  used  to  cleanse  the  labial,  buccal,  and  such  lingual 
faces  of  the  teeth  as  the  brushes  will  reach  (Figs.  345  to  351).  The 
lingual  surfaces  of  upper  and  lower  incisors  are  cleansed  with  moose- 
hide  wheels  (Fig.  344)  and  wheel-brushes.     The  approximal  surfaces  of 


456     PERICEMENTAL  DISEASES  BEGINNING  AT  THE  GUM-MABGIN. 


the   teeth   are   cleansed    with    linen    tapes    armed   with    the   pumice- 
paste.     The  gums  and  teeth,  as  a  final  measure,  are  sprayed  with  3 


per  cent,  pyrozone  to  remove  the 


111 


Fig.  352. 


George  H.  Cushing's  scalers.  The 
forms  and  general  character  of 
these  scalers  are  well  shown.  All 
the  instruments  except  No.  6  are 
Intended  to  be  used  with  the  push 
stroke.  Nos.  1  and  2  are  specially 
intended  for  application  to  the 
posterior  surfaces  of  lower  in- 
cisors; they  are  also  admirably 
adapted  for  removing  calculous 
deposits  below  the  gum  between 
molars  and  bicuspids,  and  from 
the  posterior  surfaces  of  the  last 
molars.  No.  2  can  be  passed  quite 
to  the  extremity  of  most  roots  with 
less  disturbance  to  the  soft  tissues 
than  a  thicker  or  more  rigid  in- 
strument would  cause.  Nos.  3  and 
4  are  for  removing  deposits  at  and 
below  the  gum  between  the  teeth, 
particularly  the  lower  front  teeth. 
They  can  also  be  easily  used  upon 
the  sides  of  the  roots  of  many 
teeth,  being  passed  toward  the 
apex  of  the  root  in  a  line  nearly  or 
quite  parallel  with  that  of  the 
axes.  No.  5  is  intended  to  be 
passed  between  the  lower  front 
teeth  at  or  near  the  gum  and 
then  directly  upward,  to  remove 
the  deposits  on  the  proximal  stir- 
faces.  No.  6  is  a  hoe,  and  is  in- 
tended to  be  passed  quite  to  the 
apex  of  the  roots,  where  a  hoe  is 
desired. 


pumice.  It  is  advisable  to  repeat 
the  polishing  with  precipitated  chalk 
and  the  same  carriers.  The  astrin- 
gent mouth-wash  is  advised  for  a 
week's  use  ;  at  the  end  of  this  time 
all  evidences  of  gingivitis  should 
have  disappeared,  unless  small  cal- 
culi still  remain  under  some  portion 
of  the  gum-margin,  when  their  pres- 
ence is  denoted  by  the  redness  of 
the  overlying  gum. 

The  smoother  the  surfaces  of  the 
teeth  are  made  the  longer  will  the 
redeposition  of  calculi  be  delayed. 
The  operation  described,  so  far  as 
beneficial  effects  are  concerned,  is 
one  of  the  most  important  in  the 
practice  of  dentistry.  No  case  should 
be  dismissed  before  it  is  done ;  and 
no  long  series  of  operations  should 
be  begun  before  the  cleansing.  The 
patient  should,  in  all  cases,  upon 
dismissal,  be  given  explicit  direc- 
tions as  to  mastication  and  its  im- 
portance, the  wise  regulation  of 
the  dietary,  and  the  advisability 
and  importance  of  using  antiseptic 
mouth-washes. 

Subgingival  Deposits. 


Definition. — By  subgingival  de- 
posits are  meant  calculi  which  are 
i^  I  TL""!:.  r.!  'llTt'. "'"."/":     first  deposited  in  the  annular  de- 

pression between  the  gum-margin 
and    a   tooth.       They   are   harder, 
|S  smoother,  and  much   darker  than 

T  common  salivary  calculi,  and  collect  in  much  smaller  masses ; 
they  are  not  found  upon  the  crowns  of  the  teeth,  their  encroachment 
being  in  the  direction  of  the  cementum  (Fig.  353). 

Composition. — So   far   as   imperfect   analyses   have    shown,    these 


SUBGINGIVAL  DEPOSITS. 


457 


Fig.  353. 


deposits  are  composed  of  calcium  phosphate  combined  with  undetermined 
organic  substances. 

Occurrence. — Tlic  cavity  in  which  they  are  found  is  open  to  the- 
saliva.  They  are  associated  with  marginal  gingivitis,  being  found  after 
a  marginal  catarrhal  condition  has  been  established,  and  before  any 
direct  evidence  of  degeneration  of  the  pericementum  is  observed.  So 
far  as  clinical  observations  can  indicate,  their  formation  is  in  consequence 
of  the  gingivitis ;  the  primary  causes  of  the  deposit  are,  therefore,  the 
causes  of  marginal  gingivitis,  both  predisposing  and  exciting ;  these 
causes  have  already  been  discussed.  Following  the  general  rule  of  cal- 
culus-formation, the  source  of  the  deposits  would  be,  then,  the  precipi- 
tation of  the  calcium  salts  of  the  saliva  into  the  inspissated  or  coagulated 
altered  secretion  due  to  the  catarrhal  disturbance. 

Effects. — The  direct  eflFects  of  the  deposits  are  those  of  a  persistent 
foreign  body,  a  mechanical  irritant  in  contact  with  vital  tissue.  The 
remote  eifect  depends  upon  whether  any  of  the  causes  recognized  as  pre- 
disposing to  pericemental  degeneration  exist,  such  as  anaemic,  leuksemic, 
conditions ;  disuse,  misuse,  or  overuse  of 
the  teeth,  nephritic  or  arthritic  disorders. 
Any  and  all  predispositions  in  this  direc- 
tion, it  will  be  recognized,  are  noted  in  that 
period  of  life  known  as  the  degenerative 
period,  beginning  in  most  persons  after 
the  fiftieth  year ;  minor  evidences  of  the 
advent  of  this  period  may  be  seen  as  early 
as  thirty  years  of  age,  or  even  sooner. 
Predisposing  causes,  any  of  those  named, 
existing,  and  activ^e  causes  of  gingivitis 
arising  during  this  period  of  degeneration, 
thirty  to  fifty  years  :  the  calculi  form,  and 
incite  degenerative  changes  in  the  perice- 
mentum, attended  by  a  more  or  less  constant  set  of  symptoms,  consti- 
tuting a  condition  known  as  pyorrhoea  alveolaris,  better  known  in 
America  as  Rigg's  disease.  During  the  progress  of  pericemental 
destruction  a  fourth  type  of  calculus  makes  its  appearance,  scattered  as 
small  islets  over  those  portions  of  the  tooth-root  denuded  of  peri- 
cementum (Fig.  368). 

Predispositions  to  pericemental  degenerative  changes  may  manifest 
themselves  in  limited  atrophies.  Unaccompanied  by  inflammatory 
symptoms,  and  by  no  evidences  of  local  irritation,  the  normal-looking 
gums  may  recede  from  about  the  necks  of  the  teeth,  exposing  a  variable 
amount  of  the  cementum  ;  in  molars  the  point  of  root-bifurcation  is 
frequently  exposed.     The  shrinkage  of  the  gum  may  be  confined  to  the 


(( 


/   'ill 


'~Wj 


A,  subgingival  calculus  ;  B,  receding 
pericementum. 


458    PERICEMENTAL  DISEASES  BEGINNING  AT  THE  GUM-MARGIN. 

labial  and  buccal  faces  of  the  teeth,  or  the  lingual  aspects  may  also  be 
involved.  An  atrophy  of  the  alveolar  margins  has  occurred  and  the 
point  of  pericemental  attachment  becomes  progressively  higher.  This 
atrophy  may  affect  one  or  more  of  the  teeth.  It  is  of  frequent  occur- 
rence when  the  adjoining  tooth  or  teeth  have  been  lost,  and  the  normal 
resorption  of  the  alveolar  walls  at  the  points  of  extraction  is  not 
limited  to  these  sites,  but  involves  the  alveolar  wall  of  the  tooth 
adjoining,  and  at  but  one  aspect.  The  process  is  most  marked  in  the 
lower  second  bicuspids  after  the  molars  have  been  lost.  Secondary  and 
more  rapid  degenerative  changes  may  succeed  the  slowly  advancing 
atrophy  at  any  stage  of  its  progress. 


CHAPTER   XXV. 
PYORRHCEA  ALVEOLARIS. 

While  the  term  pyorrhrea  alveolaris  implies  but  one  symptom 
common  to  several  distinct  varieties  of  disease  of  the  pericementum, 
that  of  a  flow  of  pus  fcom  the  alveolus,  it  is  generally  understood  as 
a  term  descriptive  of  degenerative  conditions  which  have  some  distinc- 
tive features  ;  these  are  a  progressive  loosening  of  the  teeth  attended  by 
a  loss  of  the  retentive  structures,  alveolar  walls  and  pericementum,  the 
loosening  of  the  teeth  being  in  a  majority  of  cases  attended  by  a  flow 
of  pus  from  the  affected  alveolus,  and  by  deposits  of  calculi  upon  the 
denuded  roots.  The  disease  ceases  spontaneously  with  the  loss  of  the 
teeth  ;  the  resorption,  loss,  or  atrophy  of  the  alveolar  wall  being  arrested 
at  any  period  of  the  disease,  if  the  affected  tooth  be  extracted. 

All  of  the  varieties  of  this  disorder,  of  which  there  are  at  least 
three  clinical  types,  are  associated  with  all  of  the  predisposing  and 
active  causes  of  degenerations  of  the  pericementum,  and  are  most  com- 
mon from  the  age  of  thirty  onward,  although  the  disease  may  in  excep- 
tional cases  appear  during  childhood,  notably  in  rachitic  patients. 

Attempts  to  include  all  cases  of  tooth-loss,  characterized  by  the 
features  above  named,  into  one  class,  based  upon  the  pathogenesis  of 
the  disease,  have  thus  far  signally  failed,  and  have  done  much  to 
increase  the  confusion  already  associated  with  theories  as  to  definition, 
causes,  prognosis,  and  treatment  of  clinical  cases. 

Disposition  has  not  been  wanting  to  assign  a  specific  form  of  infection 
as  the  causative  element  of  this  peculiar  mode  of  tooth-loss,  but  thus 
far  the  attempts  have  been  unsuccessful,  although  in  all  cases  where 
pus-formation  is  found  the  pyogenic  sta])hylococci  and  streptococci  are 
undoubted  attendants.  Miller's  experiments  in  this  direction  ^  failed 
to  isolate  any  specific  bacterium.  He  quotes  largely  from  other  experi- 
menters, notably  Galippe  and  Malassez,  whose  researches  in  the  same 
field  were  all  indeterminate. 

Leaving  aside  questions  of  direct  and  remote  causation,  the  cases 
may  be  clinically  divided  into  three  classes  : 

First,  cases  associated  with  and  arising  from  a  primary  gingivitis, 
with  the  formation  of  hard,  scaly,  dark,  annular  calculi  beneath  the 
gum-margin. 

^  Micro-organisms  of  the  Human  Mouth. 

459 


460  PYOBBHOSA   ALVEOLABIS. 

Second,  cases  in  which  gingivitis  may  not  be  marked ;  the  early 
deposits  may  be  entirely  absent ;  the  necrosis  of  the  pericementum 
advances  in  such  a  manner  as  to  warrant  the  designation  of  Black — 
phagedenic  pericementitis. 

Third,  cases  in  which  the  degeneration  and  necrosis  of  the  peri- 
cementum and  deposits  of  calculi  occur  upon  some  lateral  aspect  of  a 
tooth-root,  the  gum-margin  being  apparently  normal. 

The  differentiation  between  these  several  conditions  is  important, 
because  while  all  three  exhibit  some  features  in  common,  they  differ  as 
to  causes,  clinical  histories,  prognosis,  and  mode  of  treatment.  In  the 
first  class  pericemental  degeneration  appears  to  be  a  secondary  feature  ; 
in  the  second  the  distinguishing  feature  ;  and  in  the  third  degeneration 
and  death  of  a  circumscribed  portion  of  the  pericementum  constitute  the 
first  evidence  of  the  developed  disease.  They  all  agree  in  having  the 
diseases  of  suboxidation  as  general  predisposing  causes  of  their  occur- 
rence ;  notable  among  which  are  the  morbid  conditions  included  under 
the  head  of  the  gouty  diathesis ;  the  last  differs  from  the  others  in 
having  a  gouty  condition  as  the  probable  exciting  cause  of  the  disease. 

Pyorrhcea  Alveolaris  beginning  as  a  Marginal  Gingivitis. 

Causes. — The  causes  of  this  condition  are  both  predisposing  and 
exciting.  The  predisposing  causes  are  the  causes,  both  general  and 
local,  of  marginal  gingivitis  (which  see),  and  the  causes  which  give 
rise  to  debility  of  the  pericementum — overuse,  misuse,  and  disuse  of 
the  teeth. 

The  exciting  causes  are,  first,  those  of  marginal  gingivitis  ;  secondly, 
deposits  of  calculi ;  thirdly,  infection  of  the  irritated  tissues.  At  later 
stages  of  the  disease  other  factors  enter  into  the  case  and  modify  its 
progress ;  viz.,  looseness  of  the  tooth  and  death  of  the  pulp. 

Symptoms  and  Clinical  History. — The  symptoms  of  the  disease 
differ  at  the  stages  of  its  progress.  As  a  rule,  the  disorder  is  most  com- 
monly seen  after  its  first  stages.  The  first  stage  is  a  marginal  gingivitis  ; 
the  gum-margin  is  swollen  oedematous,  and  reddened ;  the  extent  of  the 
swelling  and  discoloration  varies  with  causes  and  individuals.  In  some 
cases  the  swelling  may  be  pronounced  and  the  gum  purplish  in  color ; 
in  others  swelling  and  discoloration  may  be  but  slight.  At  a  later 
period  an  instrument  passed  beneath  the  gum-margin  may  detect  the 
presence  of  a  scaly  collection  of  dark-green  calculus,  partially  enclosing 
the  neck  of  the  tooth.  Cases  are  seen  where  the  formation  of  this  cal- 
culus appears  to  have  preceded  any  evident  morbid  condition  of  the 
gum.  In  many  cases  the  hypersemic  condition  of  the  gum-margin 
appears  to  lessen  after  a  smooth  calculus  has  formed.  Apparently  the 
calculus  has  formed  in  consequence  of  the  union  between  the  calcium 


PYORRHCEA  ALVEOLARTS  {FIRST  CLASS). 


461 


salts  of  the  saliva  and  the  inflammatory  exudations,  the  vascular  condi- 
tions afterward  subsiding.  Infection  and  swelling  of  the  gum  are,  how- 
ever, the  usual  condition.  The  swelling  and  discoloration  persist ;  the 
calculus-formation  encroaches  further  upon  the  pericementum,  and  the 
root  becomes  progressively  denuded.  As  a  rule,  a  recession  of  the  line 
of  the  alveolar  process  is  constant  with  the  degree  of  root-denudation. 
At  any  period,  and  usually  early,  evidences  of  infection  appear;  pus 
may  be  pressed  from  beneath  the  gum-margin.  Except  in  the  later 
stages,  or  unless  pus  is  confined,  it  is  unusual  to  find  the  tooth  particu- 
larly sore  upon  percussion.  When  about  one-half  or  more  of  the  root 
has  been  stripped  of  pericementum  and  deprived  of  alveolar  support, 
looseness  and  extrusion  of  the  tooth  become  marked.  The  teeth  are 
nearly  always  looser  than  normal,  even  in  the  early  stages. 

The  advance  of  the  disease  now  becomes  more  rapid  ;  the  undue 
mobility  of  the  tooth  excites  an  inflammatory  reaction  beyond  the 
directly  infected  j)art,  so  that  soreness  and  looseness  are  further  in- 
creased. A  scaler  passed  into  the  pocket  formed  bet^veen  the  gum 
and  tooth  will  now  usually  detect  marked  roughness  of  the  root.  If 
the  latter  be  scraped,  small,  hard,  nodular  deposits  of  calculi  are 
detached  with  difficulty.  After  the  looseness  of  the  tooth  becomes 
marked,  the  pulp  of  the  tooth  is  usually  killed  by  strangulation  of  its 
vascular  supply.  Infection  of  the  dead  pulp  readily  occurs,  and  septic 
apical  pericementitis  arises.      The  symptoms   of  the  latter  condition 


Fig.  354. 


Section  of  an  upper  molar  with  its  alveolus, 
etc.,  showing  deposit  of  serumal  calculus 
under  the  gingival  borders ;  a,  o,  serumal 
calculus.    (Black.) 


Section  of  an  upper  incisor,  showing  at 
a,  a,  a  deposit  of  serumal  calculus 
within  the  free  margin  of  the  gum. 

(Black.) 


are  modified,  according  to  the  facility  with  which  the  pus  finds  vent 
along  the  degenerating  pericementum.  The  disease  proceeds  until  the 
aifected  tooth  or  teeth  are  cast  out,  the  alveolar  walls  and  pericementum 
having  entirely  atrophied.  The  disea.se  ceases  with  the  loss  of  the 
affected  teeth,  leaving  a  flattened  or  absent  alveolar  ridge  covered  by  a 


462  PYOBBHCEA  ALVEOLABIS. 

mass  of  more  or  less  spongy  gum-tissue.     The  duration  of  the  disease 
may  be  months  or  years. 

A  general  subcatarrhal  condition  of  the  mouth  usually  attends  the 

disease. 

Pathology  and  Morbid  Anatomy. — Figs.  354,  355,  and  356  exhibit 
three  distinct  relationships  of  this  form  of  calculus.  Present  data 
relative  to  the   pathology  and   morbid   anatomy  of  all   three   classes 

of  pyorrhoea  have  been  derived  from  clinical 
observations  of  teeth  in  the  mouth  and 
from  an  examination  of  teeth  which  have 
been  lost  at  some  period  of  the  disease. 

The  Teeth. — In  all  of  the  varieties  of 
pyorrhoea  it  is  the  general  rule  to  find  the 
teeth  singularly  free  from  dental  caries.  In 
a  majority  of  cases  their  forms  are  of  a  type 
considered  characteristic  of  the  bilious  and 
the  nervous  temperaments — broader  at  the 
occlusal  surfaces  and  cutting-edges  than  at 
the  necks  of  the  teeth.     Upon  section  all 

Section  of  an  uppei  mcisor,  showing       p   ,i         i       ,    i     ,•  ,       i  n 

at  a  a  deposit  of  serumai  calculus   of  the  dental  tissucs  are  secu  to   be  ot  a 
and  destruction  of  the  lower  hor-  highly  organized  type  ;  they  offer    unusual 

der  of  the  alveolar  wall  and  peri-        o      -'         o  jl      j^         j 

dental  membrane,  with  a  slight  resistance    to     cutting-mstruments.        ihe 

recession  ofthe  gum,  exposing  the    gj^^mcl    haS    a   fliut-like    hardneSS,    the    den- 
calculus.    (Black.) 

tin  is  much  increased  in  translucency, 
and  the  pulp-chamber  is  much  contracted — i.  e.,  the  formative  activity 
of  the  pulp  has  been  carried  to  its  extreme  limit.  The  pulp-tissue  is 
increased  in  density,  and  there  is  a  notable  increase  in  its  fine  fibres. 
One  section  exhibited  an  apparent  loss  of  odontoblasts  (atrophy)  over  a 
considerable  surface  of  the  pulp-periphery ;  others  of  these  cells  were 
reduced  to  comparative  flatness.  This,  however,  was  a  clearly  gouty  case. 
The  appearance  of  the  root  depends  upon  the  stage  of  the  disease 
when  the  tooth  was  lost.  In  the  early  stages  a  band  of  dark,  smooth, 
..„  scaly  calculus  surrounds  a  portion  of  the 

neck  of  the  tooth,  and  embraces  the  ce- 
mentum,  slightly  overlapping  the  enamel. 
Beyond  the  calculus  is  an  area  of  denuda- 
tion, the  cementum  free  from  pericemen- 
tum ;  beyond  this,  the  pericementum  is  in- 
tact, but  its  fibres  are  swollen,  and  its  color 
^,  thickened  pericemetitura;B,  sub-  deepened.  The  presence  of  a  ring  of  bare 
.     gingival  calculus.  cementum  between  the  pericementum  and 

the  calculus  was  constant  in  all  of  the  specimens  examined.     The  infer- 
ence is  that  after  the  primary  deposit,  necrosis  of  pericementum  precedes 


PYORRHCEA  ALVEOLARIS  (FIRST  CLASS). 


463 


subsequent  deposits.  Teeth  extracted  at  later  periods  exhibit  usually  two 
varieties  of  calculus  :  first,  that  which  formed  beneath  the  gum-margin  ; 
second,  beyond,  upon  the  denuded  cementum,  are  small  islets,  bead-like 
deposits  of  rough,  hard,  dark  calculi,  which  appear  also  in  other  dental 
conditions  attended  by  continued  pus-formation.  They  appear  identical 
with  the  deposits  which  are  found  upon  the  apices  of  roots  in  long-con- 
tinued chronic  septic  apical  pericemeutitis  (alveolo-dental  abscess),  and  on 
the  sides  of  roots  in  cases  of  the  same  disease  discharging  at  the  gum- 
margin,  in  cases  of  phagedenic  pericementitis,  and  as  secondary  deposits 
in  gouty  pyorrhoea.  Their  association  with  chronic  pus-formation 
appears  clear,  their  presence  being  evidence  of  continued  suppu- 
ration. They  are  to  be  regarded  as  resultant  from,  not  causative 
of  the  pericemental  degeneration.  They  are  more  often  present  in 
cases  of  delayed  than  in  rapid  tooth-loss.  Teeth  extracted  at  the  latest 
stages  of  the  disease  show  that  the  apical  pericementum  still  maintains 
attachment,  and  is  much  swollen.  Examining  the  tooth  or  teeth  before 
they  are  extracted,  a  pocket  is  found  to  exist  beyond  the  calculus,  and 
its  direction  and  situation  depend  upon  the  position  of  the  calculus. 
If  this  be,  as  it  frequently  is,  upon  the  palatal  surface  of  the  root,  the 
formation  of  a  pocket  at  the  labial  aspect  may  not  be  marked  until  the 
posterior  pocket  is  much  deepened. 

In  most  of  the  cases  of  the  first  class  of  pyorrhoea  a  probe  fails  to 
discover  uncovered  alveolar  bone,  although  it  may  do  so  ;  a  matter  of 
some  importance,  as  it  indicates  in  some  measure  the  mode  of  alveolar 
degeneration.  If  the  bone  be  covered, 
its  resorption  is  more  of  the  nature  of  an 
atrophy ;  if  uncovered,  it  is  probably 
lost  in  part  through  peripheral  molecu- 
lar necrosis.  The  conditions  point  to  a 
progressive  recession  of  the  pericemen- 
tum, with  the  loss  of  alveolar  wall,  as 
an  atrophy,  a  secondary  process. 

It  is  to  be  remembered  that  all  evi- 
dences of  alveolar  disease  cease  promptly 
with  the  loss  of  the  affected  teeth. 

A  condition  sometimes  met  with  is 
recorded  by  Black,  in  which  a  dual  peri- 
osteal disease  is  in  evidence  (Fig.  358). 
The  irritation  caused  by  the  presence  of 
a  subgingival  deposit  has  resulted  in  an 
atrophy  of  the  immediately  adjacent  alveolar  process;  at  the  labial 
aspect  of  the  alveolar  edge  the  pericementum  has  been  irritated  to  a 
constructive  stage  and  a  new  deposit  of  bone  has  occurred,  resulting  in 


Fig.  358. 


Section  of  an  upper  incisor,  showing  de- 
struction of  the  peridental  membrane 
and  aversion  of  the  alveolar  wall, 
with  thickening  of  its  border :  a,  seru- 
mal  calculus;  b,  thickened  border 
of  the  alveolar  wall;  c,  pus-cavity. 
(Black.) 


464  PYOERHCEA  ALVEOLABIS. 

a  distinct  thickening  of  the  alveolar  margin.  This  condition  illustrates 
well  the  effects  of  grades  of  irritation  ;  how  one  grade  is  productive  of 
increased  functional  activity,  another  of  degeneration  and  atrophy.  It 
is  rare  for  this  variety  of  pericemental  destruction  to  proceed  to  any 
considerable  depth  without  abundant  manifestations  of  pyogenic  infec- 
tion. The  infection,  however,  exhibits  no  disposition  to  invade  the 
outer  maxillary  periosteum ;  it  follows  the  direction  of  the  pericemen- 
tum, and  ceases  promptly  as  soon  as  the  teeth  are  extracted,  no  matter 
at  what  period. 

Diag-nosis. — Usually  but  little  difficulty  attends  the  diagnosis  of 
this  varety  of  pyorrhoea.     As  a  rule,  several  teeth  are  affected  ;  those  in 

in  which  the  characteristics  of  the  dis- 
FiG-  2^^-  ease  are  most  marked  are  the  upper 

incisors.  If  the  disease  is  fully  es- 
tablished, it  will  be  confounded  with 
no  other  condition  :  the  tumid  gum, 
the  presence  of  easily  discoverable 
calculi  in  a  subgingival  pocket,  and 
the  oozing  of  pus,  all  furnish  a  clin- 
ical j)icture  not  associated  with  any 
Absorption  of  the  septum  of  bone  and  re-     other    dental    disorder.      The   occur- 

cession  of  the  gum  between  the  central  „     ,  .  .    i    i 

and  lateral  incisors,  caused  by  deposits     reuce  of  thesc  pericemental  degenera- 

of  serumal  calculus  under  the  gingivae.       tious     cau    be    forCshadowed    at    timCS. 

In  any  of  the  three  forms,  evidences 
of  marginal  atrophy  of  the  alveolar  walls  may  be  noted  before  any 
deposits  of  calculi  can  be  detected,  or  before  there  are  any  indications  of 
the  initial  gingivitis ;  the  septum  of  gum  between  the  teeth  recedes, 
obliterating  the  normal  gum-festoon  (Fig.  359). 

The  existence  of  a  persistent  gingivitis,  with  an  exaggeration  of  the 
space  between  tooth  and  gum-margin,  means  a  future  pyorrhoea. 

Differential  Diagnosis. — In  the  later  stage  care  will  be  nec- 
essary to  determine  which  variety  of  pyorrhoea  is  present.  In  the  tirst 
variety  the  bottoms  of  the  pockets  are  usually  found,  not  far  be- 
yond evident  deposits  of  calculi.  Indications  of  the  existence  of  an 
annular  alveolar  wall  are  also  observed.  Gingivitis  keeps  pace  with 
the  loss  of  pericementum.  In  phagedenic  pericementitis  the  deposits 
may  only  be  recognized  with  difficulty  ;  the  degeneration  proceeds  in 
a  direct  line  toward  the  apex  of  the  root ;  the  pericementum  may  still 
be  attached  along  the  other  portions  of  the  root ;  the  gingivitis  may 
be  very  slight ;  the  gum-edge  although  receded,  may  retain  its  normal 
festoon.  In  gouty  pyorrhoea  (proper),  deposits  about  the  neck  of  the 
tooth  are  unusual,  and,  except  in  later  stages,  the  gingival  attachment 
appears  almost  normal.     A  slender  instrtiment  is  passed  Avith  some 


PYORRHCEA  ALVEOLARIS  (FIRST  CLASS).  465 

difficulty  beyond  the  gum-margin  ;  its  introduction  may,  again,  be  entirely 
resisted.  Pressure  upon  the  tooth  shows  it  to  be  loose,  and  pressure 
over  the  gum  near  the  apex  may  show  a  boggy  softness  due  to  an  out- 
lined loss  of  alveolar  wall.  The  family  and  personal  history  is  of 
great  importance. 

In  goutv  pvorrhcea,  and  in  phagedenic  pericementitis  but  few  teeth 
are  attacked  at  once,  as  a  rule ;  frequently  but  one  tooth  is  affected ;  in 
the  first  variety  several  teeth  are  attected  simultaneously. 

Prognosis.— Of  all  the  varieties  of  pyorrhoea,  the  first  is  that  having 
the  most  favorable  prognosis.  If  properly  treated  medicinally  and  me- 
chanically, proper  directions  given  the  patient,  and  frequent  super- 
vision exercised,  the  disease  may  be  arrested  in  any  but  its  latest  stages. 
If  predispositions  to  pericemental  degeneration  exist,  they  will  modify 
the  prognosis  in  the  degree  of  the  difficulty  of  eliminating  them.  The 
assertion  is  made  by  many  practitioners  that  in  their  hands  pyorrhoea 
alveolaris  is  an  entirely  curable  disease.  These  assertions  refer,  no 
doubt,  to  the  first  class,  for,  as  will  be  seen,  the  prognosis  of  the  second 
and  third  classes  of  pyorrhoea  may  be  independent  of  therapeusis. 

Treatment. — From  the  point  of  view  of  therapeutics,  several  condi- 
tions exist  in  the  morbid  phenomena  described.  First,  infection ; 
second,  the  presence  of  foreign  bodies  ;  third,  teeth  in  any  degree  of 
partial  luxation  ;  fourth,  mal-occlusion ;  fiftli,  vascular  disturljance  of 
the  gum  and  pericementum  ;  sixth,  probably  an  underlying  constitu- 
tional predisposing  cause.  Treatment  is  directed,  first,  to  a  removal  of 
all  sources  of  irritation.  The  sources  of  offence  are  to  be  removed  in 
the  order  of  their  danger  to  the  teeth.  If  the  disease  have  progressed 
far,  the  imminent  danger  is  mechanical  dislodgement  of  the  loosened 
teeth  ;  the  affected  tooth  is  to  be  lashed  to  its  firmer  neighbors,  so  that 
it  is  immovably  held.  A  careful  examination  is  next  made  of  the 
occlusal  relations  ;  in  the  majority  of  cases  the  occlusion  wall  be  found 

excessive.     The  teeth  and  in  some  cases  tlieir  an- 

1  ,  ..1  Fig.  360. 

tao-omsts  are  ground  awav  bv  means  oi   corundum 

wheels  until  they  are  slightly  short  of  occlusion. 
The  exposed  portions  of  the  crowns  and  roots  are 
scaled  free  from  all  deposits.  As  it  will  be  neces- 
sary to  hold  the  affected  teeth  immovably  during 
the  period  of  liealing,  the  nature  of  the  splint  required 
is  determined  upon.  If  but  two  or  three  anterior 
teeth  are  to  be  held,  rings  made  of  thin  platinum 
plate  form  effective  splints  (Fig.  360).  The  teeth 
to  be  splinted  are  ligated  firmly  together  at  their  necks,  and  a  strip 
of  platinum  plate,  No.  34,  is  annealed  and  moulded  against  the  lingual 
faces  of  the  teeth ;  it  is  passed  between  the  teeth  to  be  splinted  and 

30 


466 


PYORRHCEA  ALVEOLARIS. 


Fig.  361. 


those  posterior,  and  its  free  ends  are  overlapped ;  a  scratch  is  made  to 
indicate  the  overlap,  and  the  piece  is  detached  and  soldered.  Returned 
to  the  teeth,  the  thinnest  separating  saw  is  passed  between  the  teeth,  groov- 
ing the  splint  deeply  upon  both  sides ;  in  these  grooves  straight  strips  of 
platinum  plate  are  placed.  If  the  piece  can  be  lifted  from  the  teeth 
without  force,  it  is  so  displaced ;  if  not,  a  plaster  impression  is  taken, 
a  cast  of  investing  material  made,  and  the  strips  soldered  in  their 
grooves.  The  investment  and  splint  are  thrown  hot  into  sulfuric  acid, 
which  cleanses  the  splint  and  removes  the  investment  without  force. 
The  splint  is  washed  in  running  water,  the  teeth  are  wiped  off  with 
chloroform,  and  the  splint  cemented  in  place  with  zinc  phosphate. 

Where  several  teeth  are  to  be  held  a  swaged  plate  is  usually  the 
most  effective  splint.     After   the   occlusion  has  been  overcorrected,  a 

plate  to  cover  the  loose  and  the  immediately 
adjoining  teeth  is  swaged  and  cemented  to  the 
teeth  (Fig.  361). 

The  ojaerator's  ingenuity  will  show  him 
which  of  the  great  number  of  retaining  appli- 
ances devised  will  serve  best  in  a  particular 
case.  Many  of  the  retainers  used  in  ortho- 
dontia serve  admirably  as  splints.  The  splint 
position,  surgical  rest  is  assured.  The  agent  second  in  import- 
ance, as  threatening  the  pericementum,  is  the  infection.  Antiseptics 
are  to  be  freely  used  during  all  operations  and  frequently  by  the  patient 
after,  and  between  operations.  The  pockets  are  first  freely  syringed  or 
sprayed  with  hydrogen  dioxid  until  effervescence  ceases ;  wisps  of 
cotton  dipped  in  25  per  cent,  pyrozone  are  next  placed  in  the  pock- 
ets (Ottolengui) ;  a  white  eschar  forms 
at  once,  and  any  pus  or  decompos- 
ing organic  matter  remaining  is  de- 
stroyed. The  next  threatening  element 
is  the  calculus ;  so  long  as  deposits  of 
calculi  remain,  irritation  will  continue. 
Beginning  with  the  tooth  most  threat- 
ened, delicate  scalers  (Fig.  362)  are 
passed  beneath  the  gum,  and  used 
with  a  push  cut  to  chisel  away  all  depos- 
its. The  instruments  must  be  delicate 
in  order  to  detect  the  granule-like 
deposits.  The  cutting  is  to  be  firm 
and  decided,  but  slipping  of  the  instru- 
ment must  be  guarded  against  by  rest- 
ing the  fingers  upon  the  tips  of  the  teeth  (Fig.  363).     The  scraping  is 


m 


Fig.  362. 


Showing  the  application  of  a  thin,  flat 
instrument  to  the  labial  and  approxi- 
mal  surfaces  of  an  upper  bicuspid 
(pushing  motion). 


PYORRHfEA  ALVEOLARIS  {FIRST  CLASS). 


467 


alternated  by  syringing  with  liydrogen  dioxid  to  cleanse  the  pockets. 
If  much  swelling  of  the  gum  be  present,  tampons  of  cotton  saturated 
with  10  per  cent,  solution  of  trichloracetic  acid  packed  in  the  pockets 

Fig.  363. 


Showing  the  manner  of  holding  an  instrument  for  detaching  calcareous  deposits  when  using  the 
pushing  motion.  The  third  finger  rests  on  the  edges  of  the  teeth,  allowing  freedom  of  the 
hand  to  make  rapid  and  effectual  movements  in  dislodging  the  calculi. 

for  a  few  minutes  will  check  oozing  and  permit  a  better  view  of  the 
pockets.'  The  scaling  of  one  tooth  is  to  be  completed  before  passing 
to  a  second  tooth.  This,  however,  does  not  apply  to  the  first  visit  after 
splinting  the  teeth  ;  as  it  is  frequently  advisable  to  then  remove  the 
coarse  subgingival  deposits  from  all  of  the  teeth,  cleanse  the  pockets 
with  25  per  cent,  pyrozone,  and  prescribe  an  astringent  antiseptic 
mouth-wash  to  be  used  several  times  daily  for  two  or  three  days : 


^.  Zinc  chlorid, 
Aq.  menth.  pip., 


gr.  x; 

;j.-M. 


The  tumefaction  of  the  gum  will  be  much  reduced  and  pus-formation 

1  Kirk. 


468  PYOBRHCEA  ALVEOLARIS. 

checked  by  this  means.  At  the  second  visit  the  scaling  should  be  begun 
and  continued  upon  a  tooth  until  it  appears  entirely  free  from  roughness 
before  passing  to  a  second,  and  so  on.  Partial  scaling,  repeated  at  inter- 
vals, interferes  with  or  prevents  the  regenerative  process.  After  each  scal- 
ing the  pockets  are  syringed  forcibly  with  hydrogen  dioxid.  The  use  of 
acids,  particularly  two  of  the  organic  acids — trichloracetic  (Kirk)  and 
lactic  (Younger) — is  advised ;  they  have  been  found  serviceable  as  an 
application  after  scaling  and  syringing.  They  act  as  solvents  upon 
the  minute  calculi  which  escape  the  scaler,  and  as  caustics,  stimulating 
healthy  action  in  the  ulcerous  pericementum.  Unless  pus-formation  or 
congestion  persist,  the  scaled  teeth  are  to  remain  undisturbed.  After 
the  operation,  the  use,  several  times  a  day,  of  the  astringent  and  anti- 
septic mouth-wash  given  above  is  advised. 

Truman  advises  the  use  of  hydronaphtol  in  an  astringent  vehicle 
as  an  effective  germicide  for  use  by  a  patient : 

^.  Hydronaphtol,  gr.  x; 

Glycerol,  §j  ; 

Alcohol,  5J  ; 

Aq.  destill.,  Sij. — M.     (Peirce.) 
S.  Use  as  wash  several  times  a  day. 

In  case  of  recurring  or  persistent  pus-formation  the  pocket  should  be 
again  explored,  cleansed  and  dressed  as  described. 

The  splints  are  to  remain  in  position  until  the  gum  appears  to  grasp 
the  teeth  firmly,  is  of  normal  color,  and  pockets  have  closed.  If  more 
than  half  of  the  root  has  been  denuded,  permanent  splints  are  advis- 
able. Eegeneration  of  alveolar  process  does  not  occur ;  the  gum  gradu- 
ally shrinks  to  its  normal  relation  with  the  process  in  its  atrophied 
condition. 

Constant  care  upon  the  part  of  the  patient,  both  as  to  general  and 
oral  health,  and  occasional  inspection  by  the  operator  are  necessary  for 
even  reasonable  assurance  against  a  recurrence  of  the  disease.  Recur- 
rence is  more  or  less  probable,  no  matter  what  precautions  are  taken. 
Even  when  pus-  and  calculus-formation  are  not  re-established,  atrophy 
of  the  alveolar  process  is  common.  The  advent  of  these  diseases  ex- 
presses a  degenerative  impulse  against  which  the  best  of  therapeusis 
frequently  fails,  almost  entirely. 

Phagedenic  Pericementitis. 

The  term  phagedenic  pericementitis  was  suggested  by  Black  to  desig- 
nate a  condition  Avhose  most  prominent  feature  is  a  progressive  death  of 
pericementum,  beginning  at  its  marginal  attachment,  not  caused  by  me- 


PHAGEDENIC  PERICEMENTITIS.  469 

chanical  injury,  chemical  agencies,  specific  vims,  or  the  selective  action  of 
drugs  ;  and  whose  usual,  although  not  constant,  accompaninionts  are 
pus-t'ormation  and  deposits  of  calculi.  Its  progress  is  phagedenic,  and 
ceases  with  the  loss  of  the  tooth.  From  the  pus-flow  this  disease  has 
been  included  under  the  generic  head  of  pyorrhoea  alveolaris,  although 
it  is  clearly  distinguished  from  the  disease  already  described  as  due 
primarily  to  subgingival  deposits. 

Definition. — In  light  of  present  data  phagedenic  pericementitis  may 
be  defined  as  a  condition  which  comprises  degeneration,  atrophy,  and 
molecular  necrosis  of  the  alveolar  process  and  a  molecular  loss  of  peri- 
cementum, accompanied  in  its  developed  state  by  pyogenic  infection  and 
usually  by  deposits  of  nodular  calculi.  The  pericementum  and  alveolar 
process  covering  a  root  may  be  entirely  destroyed  without  any  distinct 
evidence  of  inflammation,  suppuration,  or  calculus-formation. 

Causes. — The  causes  of  this  condition  appear  to  be  divisible  into 
predisposing  and  exciting.  The  predisposing  causes  are  those  named 
as  productive  of  pericemental  debility  and  degeneration.  Among 
the  general  predisposing  causes  are  heredity,  particularly  as  to 
arthritic  diseases,  and  the  diseases  of  suboxidation  and  faulty  elimina- 
tion. Among  the  local  predisposing  causes  are  overuse,  disuse,  and 
misuse  of  the  teeth.  Overuse  and  misuse  often  act  as  direct  excit- 
ing causes.  The  primary  gingivitis  noted  as  inviting  the  first  variety 
of  ])yorrha?a  alveolaris,  appears  to  play  a  subordinate  part  in  the  causa- 
tion of  phagedenic  pericementitis,  although  it  does  usher  in  the  disease 
in  some  cases,  when  a  deposit  of  subgingival  calculus  appears  to  act  as 
the  excitino'  agent  of  the  degeneration. 

Symptoms. — It  has  been  maintained  that  this  disorder  is  essentially 
infective,  but  thus  far  all  attempts  to  di.scover  organisms  M'hich  are 
pathognomonic  have  failed.     It  is  more  than  probable,  however,  that 
future  studies  will  discover  in  bacteria   an  acute  etiological  factor  in 
the  disease.     The  symptoms  most  characteristic  and  distinctive  of  this 
disease  are  best  noted  upon  an  upper  central  incisor,  and  others  upon 
the  palatal  root  of  an  upper  molar.     At  a  period  antedating  any  evi- 
dences of  pericemental  affection  a   tooth,  frequently  an  upper  incisor, 
shifts  its  position,  moving  outw^ard,  or  rotat- 
ing and  separating  from  one  of  its  neighbors  ■ 
(Fig.  364).     There  is  no  peculiarity  of  the 
occlusion  which   will  explain  this  shifting. 
At  a  later  period — it  may  not  be  for  many 
months — the    shifted    tooth    is    seen    to    be 
looser  than   its    neighbors.     This  loosening 
is  hastened  if,  in    shifting,  a  condition   of 
mal-occlusion   is  established.     Before  the  tooth  loosens,  evidences  of 


470 


PYOBBHCEA  ALVEOLARIS. 


atrophy  of  the  alveolar  margins  may  be  seen  in  a  recession  of  the  gum- 
festoon  between  the  teeth.  As  soon  as  looseness  is  marked,  evidence  of 
pericemental  loss  may  be  detected  by  passing  an  instrument  beneath 
the  gum-margin,  which  is  seen  to  be  detached  at  some  point,  commonly 
between  the  teeth  where  the  gum-recession  was  first  noted,  or  at  the 


EiG.  365. 


Fig.  366. 


Illustration  of  a  case  of  phagedenic  pericemen- 
titis :  a,  a,  dotted  lines  representing  the  out- 
lines of  the  roots  of  the  teeth ;  6,  h,  irregular 
lines  representing  the  extent  of  the  destruc- 
tion of  the  peridental  membrane  and  -nails 
of  the  alveolus.  It  will  be  noted  that  the 
gums  appear  nearly  perfect.    (Black.) 


The  same  case  shown  in  Fig  365,  denuded 
of  the  soft  tissues  to  show  more  plainly 
the  loss  of  the  walls  of  the  alveolus. 
This  drawing  was  made  after  raising  a 
semicircular  flap  of  the  soft  tissues 
over  each  root  for  the  purpose  of  thor- 
ough exploration.     (Black.) 


labial  aspect  of  the  root  (Figs.  365  and  366).  While  the  gum-margin 
usually  presents  signs  of  irritation,  it  may  be  apparently  unaffected. 
If  gingivitis  be,  or  have  been,  present,  subgingival  calculi  will  prob- 
ably exist.  Exploration  of  the  pockets  will  show  them  to  be  the  conse- 
quence of  death  of  pericementum,  which  has  followed  the  length  of  this 

structure  along  the  side  affected  ;  the 
-^^-  ^^'^'  remainder   of    the    pericementum    and 

alveolar  process  may  be  intact.     The 
root  may  exhibit  no  roughness  what- 

FiG.  368. 


A,  calculi  of  pyogenesis ;   B,  ulcerous 
pericementum. 


A,  thickened  pericementum ;  C,  subgingival  calculus ; 
B,  calculi  of  pyogenesis. 


ever.  A  careful  exploration  usually  shows  a  portion  of  the  atrophying 
alveolar  wall  over  the  necrotic  area  to  be  denuded  ;  the  pericemental 
death  has  proceeded  more  rapidly  than  alveolar  atrophy.  The  pockets 
increase  in  size,  and  the  alveolar  process  disappears  until  the  teeth  can 
be  extracted  with  the  fingers.  It  is  unusual  for  the  pockets  to  attain  any 
considerable  depth  before  evidences  of  pyogenic  infection  occur ;  so  that 


PHAGEDENIC  PERICEMENTITIS. 


471 


pus  may  usually  be  pressed  from  the  pockets.  In  cases  where  pus-dis- 
charge is  present,  the  small  nodular  calculi  may  be  detected  upon  the 
roots. 

When  pericemental  destruction  has  involved  the  apical  pericementum 
death  of  the  pulp  occurs,  and  infection  of  the  necrosed  pulp  results ; 
abscess  forms  and  pus  discharges  via  the  pyorrhoea  pocket. 

When  the  disease  attacks  but  one  root  of  a  molar,  destruction  of  the 
pericementum  around  that  root,  death  of  half  of  the  pulp,  and  abscess- 
formation  may  result,  and  the  other  roots  be  unailected  ;  a  portion  of 
the  pulp  of  the  tooth  may  retain  its  vitality  for  some  time,  notwithstand- 
ing the  apical  abscess  upon  one  root.  In  these  cases  pus-discharge 
from  about  the  root  of  a  tooth  may  be  continued  by  the  infected  dead 
pulp,  after  all  pericementum  and  alveolar  process  are  gone  from  about 
the  root. 

While  the  disease  is  usually  first  noted  about  a  single  tooth  ;  it  is 
rare  that  a  lengthened  period  elapses  before  it  makes  its  appearance 
about  other  teeth  ;  usually  an  adjoining  tooth,  or,  it  may  be,  on  a  distant 
one.  This  disease  may  make  its  appearance  in  the  mouths  of  patients 
who  take  extraordinary  care  of  the  teeth,  in  mouths  where  the  teeth 
are  apparently  entirely  free  from  deposits,  where  the  gum  appears  nor- 
mal, and  where  the  teeth  are  free  from  caries.  It  is  of  more  frequent 
occurrence  in  dentures  comparatively  free  from  caries  than  in  those 
where  caries  prevails  or  has  prevailed. 

Morbid  Anatomy  and  Pathology. — Teeth  lost  through  this  disease 
may  exhibit  no  abnormal  appearances  at  all,  except  the  entire  absence 


Fia.  369. 


Fig.  370. 


Fig.  369.— Section  of  upper  incisor,  showing  destruction  of  its  peridental  membrane  and  alveolus 
by  phagedenic  pericementitis :  o,  gum-tissues  covering  pus-cavity  (6)  formed  by  the  destruc- 
tion of  the  peridental  membrane  and  alveolar  wall.    (Black.) 

Fig.  370.— Section  of  an  upper  moJar,  showing  destruction  of  its  membrane  and  alveolar  vrall  by 
phagedenic  pericementitis  :  a,  deposit  of  serumal  calculus ;  h,  b,  gum  covering  pus-cavity  (c,  c) 
formed  by  the  destruction  of  the  peridental  membrane  and  alveolar  wall.    (Black.) 

of  even  shreds  of  ])ericementum.     They  may  be  entirely  free  from  all 
deposits.     The  teeth  are  nearly  always  of  the  type  assigned  to  the  bil- 


472 


PYOBBHGEA  ALVEOLARIS. 


ious  and  sanguine  temperaments,  and  are  singularly  free  from  dental 
caries.  The  enamel  of  the  teeth  may  be  abraded  in  some  degree,  in 
which  case  the  areas  are  seen  to  have  a  glossy  polish.  Upon  section 
enamel  and  dentin  are  seen  to  be  of  the  highest  type  of  organization. 
The  pulp-chamber  is  much  contracted.  Data  are  wanting  relative 
to  the  condition  of  the  pulp  in  these  cases ;  but  it  is  inferred  from  the 
condition  of  the  pulp-chamber,  and  the  age  at  which  the  disease  makes 
its  appearance,  that  atrophic  changes  are  probably  present. 

An  examination  of  alveoli  and  pockets  will  show  two  types  of  the 
disease  :  those  aiFected  by  the  subgingival  deposits  and  those  without 
(Figs.  369  and  370).  The  root  is  denuded  of  pericementum  to  an  un- 
usual depth,  and  the  edge  of  the  alveolar  process  is  found  to  be  bare, 
A  pocket  may  extend  to  the  very  apex  of  the  root  upon  one  side  of  a 
root,  and  the  attachment  upon  the  opposite  side  remain  normal  for  a 
long  period  (Fig.  371).  The  alveolar  septum  between  two  adjoining 
teeth  may  be  destroyed  together  with  the  corresponding  portions  of 
pericementum,  and  the  remainder  of  pericementum  upon  both  teeth 
remain  intact  for  a  long  period.  In  cases  Avithout  deposits  an  absence 
of  gingivitis  is  frequently  noted ;  even  more,  an  atrophy  of  the  gum- 
tissue  occurs  which  bares  to  some  extent  the  denuded  root.  Where 
subgingival  deposits  are  present,  gingivitis  is  the  rule.  The  effects 
of  the  occurrence  of  constructive  pericementitis  upon  the  outer  alveolar 
margin  may  be  noted  in  some  of  the  long-continued  cases. 

Fig.  371. 


Showing  loss  of  pericementum  and  alveolar  process  over  one  face  of  one  root  of  a  molar  tooth  from 
phagedenic  pericementitis.  Several  of  the  other  teeth  were  the  seat  of  the  first  variety  of 
pyorrhoea. 


What  was  said  of  the  first  variety  of  pyorrhoea,  relative  to  the  loca- 
tion of  the  disease,  applies  with  equal  force  to  phagedenic  pericemen- 
titis. It  is  a  disease  of  the  pericementum,  and  alveolar  necrosis  is  a 
secondary  feature,  which  ceases  as  soon  as  the  teeth  are  lost  by  extrac- 
tion or  by  the  progress  of  pericemental  necrosis.  There  is  an  atrophic 
variety  of  the  disease  which  exhibits  peculiar  features.  Marginal  alveo- 
lar atrophy  is  seen  to  occur  about  the  roots  of  several  teeth.  There 
is  no  vascular  disturbance  in  the  gum-tissue,   so   that  the   gum-line 


PHAGEDENIC  PERICEMENTITIS.  473 

recedes  with  the  alveolar  wall.  The  ceinentuni  of  the  root  becomes 
exposed  almost  always  at  the  labial  or  buccal  aspects.  Later,  death  of 
an  annular  portion  of  pericementum  and  infection  by  pyogenic  organ- 
isms occur ;  immediately  beneath  the  gum-margin  small,  hard,  nodular 
calculi  are  formed.  Instead  of  deep  pockets,  the  pericemental  loss  is 
attended  by  a  constant  recession  of  the  gum-line  until  the  roots  of 
the  teeth  become  exposed  for  a  great  part  of  their  length  ;  the  reces- 
sion of  the  gums  exposes  the  calculi  which  have  formed  (Fig.  372j. 

Fig.  372. 


The  alveoli  irreparably  destroyed  by  calcic  inflammation.    (Black.) 

This  process  is  far  from  uncommon  in  the  mouths  of  persons  who  pos- 
sess fine  dentures,  but  who  neglect  the  care  of  their  mouths. 

Diagnosis. — The  differential  diagnosis  of  phagedenic  pericementitis 
from  the  first  and  third  varieties  of  pyorrhoea  has  been  given  in 
connection  with  the  first  variety.  Its  direct  diagnosis  consists  in  dis- 
covering the  peculiar  pockets,  denuded  roots,  and  alveolar  edge.  Its 
occurrence  can  almost  be  certainly  foretold  in  the  mouths  of  patients 
who  have  fine  dentures  of  the  type  described,  who  have  particularly  an 
arthritic  history,  and  who,  about  the  age  of  thirty  or  later,  note  the 
change  of  position  of  one  or  more  teeth  without  evident  cause.  It  Avill 
be  recalled  that  the  pockets  in  phagedenic  pericementitis  have  a  depth 
out  of  all  proportion  to  their  lateral  extent. 

As  pointed  out  by  Black,  the  condition  may  be  confounded  with 
apical  abscess  opening  along  the  side  of  a  root.  If  the  latter  be  acute, 
the  acute  symptoms  of  alveolar  abscess,  absent  in  phagedenic  perice- 
mentitis, point  to  a  diagnosis.  If  chronic,  there  may  be  noted  evi- 
dences of  pulp-death,  absent  response  to  thermal  stimuli,  and  the  pres- 
ence of  large  fillings.  An  examination  should  be  made  of  the  other 
teeth,  for  it  is  unusual  that  phagedenic  pericementitis  will  progress  to 
the  end  of  the  root  of  a  single  tooth  before  other  teeth  are  involved. 
Doubt  will  be  dispelled  by  opening  the  affected  tooth,  Avhether  carious 
or  non-carious.  If  the  pulp  be  alive,  it  is  phagedenic  pericementitis ; 
if  dead,  it  may  be  that  or  alveolar  abscess.  If  the  latter,  a  cure  is 
accomplished  by  treatment  as  described  in  Chapter  XXII. 


474  PYOBBHCEA  ALVEOLABIS. 

Prognosis. — The  prognosis  of  this  disease,  so  far  as  the  teeth  affected 
are  concerned,  is  in  general  decidedly  unfavorable.  While  it  may  be  tem- 
porarily arrested  in  its  earlier  stages,  its  recurrence  and  ultimate  loss  of 
the  aifected  teeth  are  the  rule.  It  may  attack  but  few  teeth  of  a  denture 
and  progress  until  they  are  lost,  the  other  teeth  remaining  unaffected. 
The  common  history,  however,  is  that  when  the  disease  makes  its  appear- 
ance the  denture  is  ultimately  lost  through  it,  although  the  period  of  loss 
may  cover  many  years.  Several  years  may  elapse  between  the  loss  of 
one  tooth  and  the  aifection  of  the  second,  Upjoer  incisors  and  molars 
appear  to  suffer  more  frequently  from  the  disease  than  any  of  the  other 
teeth. 

Treatment. — Treatment  of  the  case,  based  upon  the  relief  of  dis- 
coverable morbid  conditions,  will  serve  to  stay  the  process.  The  con- 
ditions demanding  correction  are,  faulty  occlusion,  undue  mobility,  the 
presence  of  necrotic  tissue,  usually  an  infection  and  foreign  deposits. 
These  latter  are  to  be  regarded  as  pathogenic  in  that  they  prevent  a 
return  to  health  of  the  gum-tissue  overlying  them. 

The  treatment  is  both  prophylactic  and  remedial.  Patients  having 
an  arthritic  history  and  the  type  of  denture  named  should  be  warned  of 
the  dangers  of  establishing  a  pericemental  debility  through  relative  dis- 
use of  the  teeth,  and  of  permitting  morbid  gingival  conditions  to  arise 
from  neglect  of  oral  hygiene.  The  relations  of  food-habit  and  gen- 
eral disease,  notably  those  of  suboxidation,  to  dental  disease  are  to  be 
pointed  out. 

In  the  early  stages  of  pyorrhcea,  that  of  tooth-shifting,  it  has  been 
asserted  ^  that,  if  the  tooth  be  opened,  the  pulp  destroyed,  and  canal 
filled,  the  impending  degeneration  and  necrosis  of  the  pericementum 
will  be  averted.  There  is  good  clinical  evidence,  both  of  the  writers 
quoted  and  others,  to  substantiate  the  assertions.  The  probable  expla- 
nation is  that  the  diversion  of  the  apical  blood-supply  entirely  into  the 
pericementum  protects  this  structure  against  threatened  degeneration. 
There  is  reason  to  believe,  although  histological  data  in  this  connec- 
tion are  wanting,  that  changes  in  the  bloodvessels  and  nutrition  of 
the  pericementum  are  antecedents  to  the  degenerative  and  necrotic 
changes  described.  When  the  pockets  have  formed  and  alveolar 
atrophy  is  marked  the  conditions  resemble  in  some  particulars,  but  are 
bv  no  means  identical  with,  those  noted  in  connection  with  the  first 
variety  of  pyorrhcea. 

The  treatment,  as  regards  splinting  of  the  teeth  and  sterilization  of 

the  pockets,  is  the  .same  as  in  the  first  class.     Black  emphasizes  two 

points  of  much  importance  in  the  next  stage  of  treatment — i.  e.,  the 

removal  of  deposits — first,  that  the  gum-margin  must  not  be  unnec- 

1  M.  L.  Ehein  ;  D.  D.  Smith. 


PHAGEDENIC  PERICEMENTITIS. 


475 


Fig.  373. 


Scalers    (three    times 
natural  size). 


essarily  injured ;  secondly,   that  vigorous  scaling  of  the  roots  may  be 

done   without  special  regard   to  avoid    cutting   the   tissues   lining    the 

pocket,  instead  of  avoiding    such  injury,  as  in  the 

first   class    of  pyorrhcea.      The   pockets   are   freely 

syringed   with    hydrogen  dioxid,   or  with   a   1  :  500 

solution    of  mercuric    chlorid    in    hydrogen    dioxid. 

The    alveolar  edges  are    to    be    freely  scraped  with 

the  scaling  instruments,  which  should  have  slender 

stems  and  comparatively  broad  cutting-blades  (Fig. 

373).      The  use  of  cauterants,  such  as  trichloracetic 

and  lactic  acids,  is  more  important  than  in  the  former 

type    of  disease.       The    same    astringent   antiseptic 

washes  are  to  be  prescribed.      After  removing  all 

foreign  material,  includino;  dead  matter  and  steriliz- 

ing,  correcting  occlusion,  and   securing  immobility, 

the  astringent  antiseptic  wash  is  expected  to  draw 

the  tissues  tightly  about  the  teeth  and  to  prevent  infection,  so  that  a 

regenerative  process  can  be  established  in  the  vital  tissues  of  the  former 

disease-pocket. 

In  case  the  pockets  are  so  deep  or  have  such  form  that  the  alveolar 
margins  cannot  be  well  trimmed  without  overstretching  or  injuring  the 
gingival  edges,  Black  advises  that  gum- 
flaps  be  raised,  exposing  the  alveolar 
margins  (Fig.  374).  A  semicircular 
incision  is  made  and  turned  back,  and 
bleeding  checked.  By  means  of  sharp 
chisels  the  alveolar  borders  are  freely 
scraped,  the  pockets  are  flushed  with 
hydrogen  dioxid,  and  the  flap  secured 
by  a  couple  of  stitches.  The  same 
writer  advises  in  cases  where  eversion 
of  the  alveolar  margin  has  occurred,  that  the  process  be  exposed  by 
cuts  and  broken  down  by  three  cuts  made  with  a  sharp  chisel  and 
mallet ;  the  loosened  segment  of  bone  to  be  pressed  firmly  against  the 
root.  It  is  desired  next  that  the  entire  pocket  will  fill  with  granula- 
tion-tissue, and  organization  of  the  granulations  take  place,  furnishing 
re-attachment.  That  this  occurs  in  some  cases  is  undoubted.  Black 
believes  that  a  reproduction  of  alveolar  margins  also  occurs  in  some 
cases.  The  hope  of  good  results  lies  in  keeping  the  parts  aseptic  after 
all  foreign  deposits  and  dead  material  have  been  removed. 

A  great  number  of  agents  have  been  advised  as  medicinal  applica- 
tions to  the  disease-pockets.  They  are  all  antiseptic  and  most  of  them 
cauterants.     These  are  to  be  used  after  the  primary  cleansing.     During 


Fig.  374. 


Illustration  of  the  position  and  form  of 
incision  through  the  gum  for  exposing 
the  root  of  the  tooth  and  injured  alveo- 
lar process  ;  a,  incision.    (Black.) 


476  PYOBBHCEA  ALVEOLABIS. 

the  period  of  granulation  no  solutions  stronger  than  stimulants  should 
be  used.  A  20  per  cent,  solution  of  zinc  iodid  (Harlan),  the  hydro- 
naphthol  solutions  (Truman),  and  the  zinc-chlorid  wash  primarily  given 
may  all  be  taken  as  representative  medicines.  The  indiscriminate  use  of 
strong  solutions  of  antiseptics  retards  the  granulating  process.  The 
silver  salts,  lactate  and  citrate,  3  per  cent,  solutions  of  silver  nitrate, 
and  powdered  nosophen  should  be  mentioned  as  useful  agents  in  this 
connection,  particularly  the  silver  salts. 

The  records  of  experiments  with  sponge-grafts  are  not  encouraging, 
there  being  too  great  difficulty  in  maintaining  them  sterile. 


CHAPTER   XXYI. 

DISEASES   OF    THE    PERICEMENTUM    BEGINNING    UPON    A 
LATERAL  ASPECT  OF  THE  TEETH. 

Gouty  Pericementitis. 

From  its  common  occurrence  in  persons  who  are  the  victims  of  the 
gouty  or  arthritic  diathesis,  a  third  variety  of  pyorrhoea  alveolaris  has 
been  designated  as  gouty  pericementitis. 

Definition. — Gouty  pericementitis  may  be  defined  as  a  condition  in 
which  degeneration  and  necrosis  of  the  pericementum  begin  in  some 
portion  of  that  structure  between  the  apex  of  a  root  and  the  gum- 
margin,  usually  attended  by  a  deposit  of  calculus  in  the  disease-area, 
which  exhibits  a  combined  reaction  of  urates  and  of  calcium  phosphate. 
As  noted  in  connection  with  the  first  and  second  varieties  of  pyorrhoea, 
many  general  diseases  included  in  the  family  of  diseases  called  gouty, 
act  as  predisposing  factors  in  their  causation.  In  the  third  variety,  not 
only  does  a  gouty  condition  act  as  a  predisposant,  but  it  appears  to 
furnish  also  the  exciting  cause  of  the  disease. 

The  pathology  and  pathogenesis  of  the  disease  will  be  more  evident 
after  a  survey  of  its  clinical  history  and  symptoms,  and  a  review  of  the 
mode  of  action  of  the  gouty  poison.  For  many  years  gout  and  the 
gouty  diathesis  have  been  recognized  as  causative  of  a  number  of  local, 
including  among  them,  several  dental  diseases,  periodical  dental  neural- 
gias, pericementitis,  and  phagedenic  destruction  of  the  pericementum.  In 
1886  AV.  J.  Reese  ^  pointed  out  clearly  the  association  of  the  gouty  condition 
with  what  he  termed  "  phagedena  pericementi."  In  1891  J.  S.  Marshall 
demonstrated  the  analogy  of  certain  pericemental  degenerations  with  a 
gouty  condition.  Impetus  was  given  the  study  of  this  association  when,  in 
1892,  C.  N.  Peirce  demonstrated  that  deposits  found  upon  the  lateral 
aspect  of  the  pericementum  gave  a  murexid  reaction,  proving  the  presence 
in  them  of  urates,  the  salts  found  in  gouty  concretions  in  other  parts 
of  the  body.  He  also  pointed  out  that  the  deposits  occurred  without 
primary  destruction  of  the  marginal  pericementum,  so  that  the  primary 
disease-focus  is  found  upon  some  portion  of  pericementum  lying  between 
the  root-apex  and  gingival  attachment. 

Symptoms  and  Clinical  History. — The  symptoms  of  gouty  dental 
diseases  depend  upon  the  stage  at  which  they  are  seen.  In  the  earliest 
stages  vague  functional  disturbances  appear  before  there  is  any  evidence 

^  Dental  Cosmos. 

477 


478  '  DISEASES  OF  THE  PERICEMENTUM. 

whatever  of  structural  changes.  Like  other  gouty  affections,  dental 
gout  rarely  makes  its  appearance  before  thirty  years  of  age,  and  most 
frequently  between  forty  and  fifty-five  years. 

Beginning  with  the  earliest  visible  evidence  of  disorder,  dental  gout 
appears  to  exhibit  itself  about  as  follows  :  in  the  mouths  of  persons 
presenting  a  clear  family  history  of  gout,  or  of  rheumatoid  arthritis  in 
the  female  line,  who  have  been  the  victims  of  gout,  evident  or  obscure, 
more  often  the  latter,  or,  again,  suffer  from  the  condition  called 
"  lithsemia "  (professional  man's  gout),  it  is  commonly  noted  that  the 
teeth  are  singularly  exempt  from  dental  caries.  This  is  a  general, 
although  not  universal  truth.  The  teeth  are  frequently  of  highly  organ- 
ized type,  and  of  the  variety  said  to  be  indicative  of  the  bilious  or 
nervous  temperament.  Frequently  they  are  the  seat  of  mechanical 
abrasion ;  their  occlusal  faces  may  be  worn  to  any  extent,  the  character 
of  the  wearing  depending  upon  the  nature  of  the  occlusion  ;  it  is  less 
marked  in  teeth  having  long  cusps  than  in  those  having  an  originally 
short  overbite.  The  long  cusps  show  the  spots  of  enamel-wear  as  areas 
having  a  glossy  polish.  Erosion  (which  see)  is  of  frequent  occurrence 
in  such  dentures,  particularly  among  females.  The  dentures  are  of  the 
class  in  which  phagedenic  pericementitis  is  apt  to  make  its  appearance. 

In  the  mouth  and  about  the  jaws  of  such  an  individual,  after  the 
age  of  thirty,  neuralgic  pains  may  be  of  nightly  occurrence ;  these 
pains  are  vaguely  referred  to  the  teeth.  An  examination  of  the 
teeth  exhibits  no  direct  reason  for  their  occurrence  ;  there  may  be  no 
dentin-exposure  and  no  tenderness  upon  percussing  the  teeth.  It  will 
be  noted,  though,  that  the  response  of  the  teeth  to  thermal  changes  is 
decidedly  increased  :  a  general  heightened  sensitivity  of  the  dental  pulps 
exists.  These  pains  and  the  pulp-hypersensitivity  disappear  after  a  time. 
In  some  cases  this  may  be  spontaneous  ;  in  others  it  will  be  found  that 
the  patients  have  been  receiving  general  medical  treatment,  and  the 
maxillary  pains  disappear  with  the  cure  of  the  disorders  treated  by  the 
general  practitioner.  At  later  periods  occasional  attacks  of  general 
pericemental  tenderness  may  occur,  which  make  their  appearance  and 
disappear  as  did  the  maxillary  neuralgia.  In  both  cases  there  is  a 
return  to  apparently  complete  normality.  These  symptoms  are  also  of 
frequent  occurrence  in  the  mouths  of  patients  who  suffer  from  dental 
erosion  and  abrasion.  The  exposed  dentin  in  these  cases  furnishes  a 
tangible  cause  for  the  reflex  pains  about  the  jaws. 

If  the  teeth  be  examined  after  this  period,  the  comparative  exemp- 
tion from  caries,  and  usually  from  calculous  deposits,  is  noted,  together 
with  the  firm  fixation  of  the  teeth  in  dense  alveolar  process.  However, 
a  slight  recession  of  the  gum-line  may  be  noted,  as  though  a  very 
limited  marginal  alveolar  resorption  had  occurred.     Later,  periods  of 


GOUTY  PERICEMENTITIS.  479 

pericemental  soreness  may  be  more  frequent,  and  one  or  several  teeth 
during  this  period  are  loosened  from  their  former  firm  implantation. 
The  soreness  may  disappear,  but  the  slight  looseness  of  the  tooth  may 
remain. 

It  is  at  later  periods  and  in  some  single  tooth,  that  degenerative  and 
necrotic  changes  become  unmistakable.  Some  one  tooth  of  a  denture 
becomes  sore  and  tender  upon  percussion  ;  the  gum  overlying  the  apical 
half  of  the  root  exhibits  the  evidences  of  an  underlying  inflammation. 
The  tooth  is  loosened,  but  the  attachment  of  the  gum-margin  remains 
unbroken  ;  indeed,  unless  the  inflammation  be  marked  there  may  be  no 
evidence  of  marginal  gingivitis.  The  symptoms  closely  resemble  those 
of  acute  septic  apical  pericementitis,  although  less  in  degree.  The 
inflammation  may  subside  and  leave  the  tooth  permanently  loose.  In 
other  cases  a  circumscribed  swelling  appears,  indistinguishable  from  that 
of  acute  apical  abscess ;  the  surrounding  inflammation  is,  however,  less. 
If  an  incision  be  made  into  this  swelling,  a  glairy,  mucus-like  discharge 
may  vent ;  in  other  cases  a  flow  of  pus  is  observed.  In  the  latter  case 
pyogenic  infection  is  certainly  present ;  in  the  other,  infection  is  uncer- 
tain. Many  of  these  cases  have  been  diagnosed  as  septic  apical  peri- 
cementitis due  to  dead  pulp :  the  tooth  being  probably  non-carious,  the 
death  of  the  pulp  is  assigned  to  one  of  the  conditions  described  under 
diseases  of  the  pulp.  Upon  drilling  into  the  tooth  dentinal  sensitivity 
may  appear  to  be  absent,  and  the  instrument  may  be  plunged  into  a  vital 
pulp — i.  e.,  the  inflammation  and  suppuration  have  no  connection  with 
a  dead  pulp.  If  the  incision  into  the  abscess-cavity  be  enlarged  and 
bleeding  checked,  it  will  be  seen  that  a  portion  of  the  alveolar  wall  has 
disappeared,  exposing  the  side  of  the  root  of  the  tooth,  which  is 
found  to  be  denuded  of  a  portion  of  its  pericementum,  and  on  the  root 
rough  bodies  are  noted,  which  if  scraped  away,  are  seen  to  be  calculi. 

In  some  cases  the  symptoms  of  pericementitis  persist  without  the 
formation  of  a  circumscribed  swelling  over  the  root,  and  later  a  discharge 
of  glairy,  mucus-like  material  or  of  pus  exudes  from  beneath  the  gum- 
margin.  The  same  errors  of  diagnosis,  and  discovery  of  live  pulp  noted 
above,  are  frequently  made.  In  other  cases  the  pericemental  destruction 
may  be  so  extensive  and  accompanied  by  a  disappearance  of  such  an 
amount  of  alveolar  process  that  the  teeth  are  very  much  loosened.  If 
the  teeth  be  non-carious,  as  they  usually  are,  and  the  looseness  have 
not  been  marked,  an  examination  of  the  interior  of  the  tooth  shows 
uniformly  the  presence  of  vital  pulp.  Teeth  have  been  extracted 
during  this  period,  one  of  which  exhibited  these  significant  features  : 
the  apical  pericementum  was  intact,  as  was  also  that  portion  toward  the 
gingival  margin  ;  between  the  two  was  an  area  of  denudation,  in  which, 
loosely  attached  to  the  root,  was  a  rough,  irregular  calculus  (Fig.  376). 


480  DISEASES  OF  THE  PERICEMENTUM. 

Calculi  scraped  from  the  roots  of  such  teeth  exhibit  in  a  varying  degree 
a  response  to  the  murexid  test,  the  test  for  urates.    The  reaction  may  be 


A  and  C,  vital  pericementum ;  B,  gouty  calculus ;  D,  a        A,  calculus  in  area  of  necrosis ;  B  and 
subgingival  calculus.  C,  vital  pericementum. 

very  faint  in  some  cases,  being  overshadowed  by  the  calcium  phosphate, 
which  makes  up  the  bulk  of  these  masses ;  in  others  it  is  pronounced — 
i.  e.,  urates  make  up  a  portion  of  the  deposit. 

A  significant  feature  is  that  in  the  irritative  and  inflammatory  stages 
of  the  disease,  except  in  those  where  pus  forms,  if  the  patient  receive 
vigorous  anti-gout  treatment,  the  dental  inflammation  subsides. 

While  pericemental  irritation  may  involve  many  teeth,  acute  out- 
breaks are  usually  confined  to  but  one  or,  at  most,  two  teeth.  The 
disease  subsequently  attacks  other  teeth  singly,  although  these  may 
escape  involvement  for  years. 

Diagnosis. — The  symptoms  and  clinical  history  given  clearly  dif- 
ferentiate this  condition  from  the  pyorrhoea  due  to  subgingival  deposits 
and  phagedenic  pericementitis.  When,  however,  the  discharge  of  pus 
at  the  gum-margin  occurs  the  case  may  be  indistinguishable  from 
phagedenic  pericementitis ;  the  difficulty  of  differentiation  is  all  the 
more  increased  from  the  fact  that  both  occur  in  patients  affected  by  the 
same  classes  of  general  disorders.  In  phagedenic  pericementitis,  however, 
some  local  explanation  of  the  disease-process  may  be  elicited ;  in  gouty 
pyorrhoea  the  symptoms  may  arise  and  the  disease  progress,  frequently 
to  its  end,  without  any  evident  local  sources  of  irritation,  except  that  in 
some  cases,  sources  of  pericemental  debility  exist  in  faults  of  occlusion, 
leading  to  overuse,  disuse,  or  misuse  of  the  teeth. 

Mode  of  Action  of  the  Gouty  Poison. — The  conditions  called  gouty 
are  held  to  be  due  to  the  retention  in  the  circulating  fluids  of  an  excess 
of  urates,  a  waste-product  of  tissue-  and  food-metaboHsm ;  this  excess 
of  material  acts  as  an  irritant  and  inflammation-exciting  agent  in  the 
tissues  of  the  body,  producing  alterations  of  function  and  structure  in 
many  tissues  and  organs,  but  most  palpably  in  the  members  of  the  con- 


GOUTY  PERICEMENTITIS.  481 

nective-tissue  group.  The  association  of  an  excess  of  urates  with  gout 
was  demonstrated  by  Garrod,  who  detected  crystals  of  urates  in  the 
serum  of  blisters  from  gouty  patients.  The  association  became  still 
more  clear  after  an  examination  of  the  calculi  of  gout,  which  were  found 
to  contain  urates.  In  gouty  joint-atfections  urates  of  sodium  are  found 
in  the  diseased  areas. 

Uric  acid  belongs  in  the  group  of  animal  poisons  generated  in  tlie 
living  tissues  of  the  body,  to  the  general  class  of  leucomains.  It  is  an 
oxidation-product  of  albuminous  matter.  There  is  a  series  of  these  sub- 
stances formed  in  the  body,  each  representing  a  degree  of  albuminous 
decomposition  by  oxidation.  The  first  and  least  oxidized,  is  hypoxan- 
thin ;  second,  xanthin  ;  third,  uric  acid ;  and,  fourth,  urea,  a  substance 
freely  soluble  in  blood-serum,  which  is  excreted  by  the  normal  kidneys 
as  a  product  of  the  nitrogenous  waste  of  the  body.  That  uric  acid 
is  formed  instead  of  a  corresponding  amount  of  urea  in  conditions  of 
faulty  oxidation,  is  the  general  opinion  of  pathologists  of  the  present 
day,  an  opinion  not  entirely  demonstrable,  as  criticism  ^  will  show  ;  still, 
it  furnishes  the  only  tangible  explanation  of  the  conditions  of  its  for- 
mation and  action  at  present  available.  Uric  acid  exists  in  the  blood- 
serum  as  a  quad-urate  of  sodium  and  magnesium.  Sodium  bi-urate 
is  relatively  a  very  insoluble  material ;  if  the  sodium  be  displaced  by 
lithium  or  potassium,  the  urates  of  these  metals  are  formed,  wliich  have 
a  greater  degree  of  solubility. 

If  for  any  reason,  notably  disease  of  the  kidney,  the  excretion  of  the 
urates  be  interfered  with,  they  accumulate  in  the  circulating  fluids,  caus- 
ing an  excess  of  urates  without  an  increased  production.  Its  increase 
may,  on  the  other  hand,  be  due  to  increased  formation  of  uric  acid.  This 
is  observed  following  upon  the  ingestion  of  unusual  amounts  of  niti'o- 
genous  foods.  After  the  consumption  of  malt  liquors  and  sweet  wines, 
particularly  champagne,  an  increase  of  uric  acid  is  observed,  showing 
that  food-metabolism  as  well  as  tissue-metabolism  is  concerned  in 
the  production  of  its  excess.  An  increased  production  is  also  noted  in 
conditions  where  there  is  an  increased  production  of  leucocytes  and  a 
diminution  of  the  red  corpuscles — the  oxygen-carriers — so  that  the  for- 
mation may  be  clearly  traceable  to  a  deficiency  of  oxygen  carried  to 
the  tissues. 

Another  point  to  be  noted  is  that  an  accumulation  of  waste-products, 
even  a  slowing  of  the  lymph-flow  about  cells,  interferes  seriously  with 
oxidation,  even  though  oxygen  be  present  in  normal  amount.  The 
existence  of  these  conditions,  which  cause  sluggish  vascular  flow  to 
and  from  tissues,  must,  therefore,  be  regarded  as  an  important  factor  in 
the  presence  of  an  excess  of  the  products  of  insufficient  oxidation. 

^  Levison,  Gout,  1896  ;  Luff,  Croonian  Lectures,  1897. 
31 


482  DISEASES  OF  THE  PERICEMENTUM. 

Under  some  conditions  deposits  of  crystals  of  urates  occur  in  the 
connective  tissues  of  the  body,  mainly  those  in  which  the  circulation 
and  the  nutritive  currents  are  sluggish,  as  in  articular  cartilages,  usu- 
ally of  small  joints ;  that  is,  the  deposits  occur  in  parts  not  freely 
flushed  by  the  movements  of  intercellular  fluids. 

Ebstein  believes  that  local  tissue-changes  precede  and  determine  the 
point  of  attack  and  deposition.  His  opinion,  as  originally  set  forth,^ 
was  that  coagulation-necrosis  of  the  cells  of  a  part  occurred,  and  the 
tissues  acquired  an  acid  reaction,  which  determined  the  precipitation  of 
urates  in  the  area. 

Van  Noorden^  believes  that  the  point  of  deposition  is  determined 
by  the  local  formation  of  a  ferment,  and  that  the  deposition  is  indepen- 
dent of  an  excess  of  urates  in  the  circulation. 

A  predisposition  to  degenerative  changes  exists  in  the  tissues  of  gouty 
patients,  notably  in  the  arteries,  leading  to  atheromatous  changes,  caus- 
ing increased  arterial  rigidity.  These  changes  are  in  part  explainable 
by  the  presence  of  an  excess  of  the  waste-product — urates.  Certainly 
in  gouty  patients,  before  deposits  of  urates  occur  and  cause  their  char- 
acteristic effects,  changes  in  many  fibrous  tissues  are  observed  which  are 
only  explainable  by  constant  irritation.  Fully  developed  gout  repre- 
sents a  degenerative  and  partially  necrotic  disease  ;  but  antedating 
these  changes,  it  appears  that  there  is  an  irritative,  perhaps  preceded  by 
a  stimulative  stage. 

Increase  of  connective  tissue,  as  in  atheroma  of  arteries,  beneath 
mucous  membranes  and  other  situations  is  found  in  gouty  patients  before 
any  history  of  acute  outbreaks  is  noted. 

Such  functional  disorders  as  neuralgia,  no  doubt  due  to  anatomical 
changes,  are  also  observed.  All  of  these  point  to  a  long-continued 
period  of  irritation  leading  to  an  increased  formation  of  connective 
tissue.  A  corollary  of  this  state  is  a  diminished  vascularity,  followed 
by  diminished  nutrition,  hence  debility  of  the  part  affected. 

Given,  then,  a  cause  of  tissue-debility,  such  as  overuse  or  disuse  of 
a  part,  with  an  accumulation  of  the  waste-product,  urates,  the  deposi- 
tion of  these  salts  is  probable  in  the  ill-nourished  and  debilitated  tissue 
or  structure,  such  as  small  joints.  It  will  be  recalled  that  the  metatarso- 
phalangeal joint,  from  its  anatomical  situation,  is  one  of  the  joints  of 
the  body  subjected  to  the  greatest  use  ;  and  lack  of  normal  exercise  of 
it  (disuse)  would  be  followed  by  its  debility,  and  determine  in  a  gouty 
patient  the  deposition  of  urates  in  it.  These  deposits  occur  first  in  the 
least  vascular  part,  upon  the  surfaces  of  the  articular  cartilage,  and 
excite  irritation  ;  if  present  in  sufficient  amount,  inflammation  of  the 
surrounding  vascular  parts  is  aroused,  and  necrosis  of  the  tissues  which 

^  Flint's  Practice  of  Medicine,  6th  ed.      '^  Medical  News,  Nov.,  1895;  and  Ziegler. 


GOUTY  PERICEMENTITIS.  483 

are  the  seat  of  the  dejjosit  occurs.  This  constitutes  tlie  condition  of 
acute  gouty  outbreak.  Any  of  the  joints  may  be  attacked,  although 
usually  it  is  one  of  the  small  joints,  most  frequently  the  metatarso- 
phalangeal. 

Gout,  or  uric-acid  poisoning,  may  exist  as  a  chronic  affection  without 
acute  outbreaks ;  deposits  accumulate  in  small  joints  (tophi),  as  of 
the  fingers,  causing  stiffness  and  deformity,  as  the  joints  are  successively 
affected.  An  injury  to  a  joint  may  determine  the  affection  in  that  joint, 
and  any  joint  may  be  affected  (Flint). 

Gout  may  exist  as  an  obscure  affection  without  any  of  the  joint- 
affections  noted.  Disorders  of  the  stomach,  liver,  kidneys,  heart,  blood- 
vessels, and  lungs  may  all  attend  chronic  gout,  and  be  caused  by  it. 
The  evidence  of  connection  of  obscure  conditions,  such  as  headache, 
hebetude  of  mind,  lassitude,  digestive,  circulatory,  or  respiratory  troubles, 
with  the  gouty  condition  may  only  be  made  manifest  by  their  relief 
through  anti-gout  therapeusis. 

All  forms  of  gout  are  largely  hereditary.  The  manifestation  of  the 
diathesis  may  skip  one  generation  and  appear  in  the  next.  Hereditary 
gout  in  the  female  may  manifest  itself  as  rheumatt)id  arthritis.  In  a 
proportion  of  cases  no  heredity  can  be  traced,  although  the  existence 
of  gout  in  the  individual  is  unmistakable. 

The  deposits  in  gout  are  only  readily  detected  when  they  exist  as 
defined  concretions.  They  may  be  present  as  fine  crystals  and  escape 
detection. 

Patholog-y. — The  test  of  the  soundness  of  the  theory  that  there 
are  distinctive  gouty  dental  affections  depends  upon  whether  their 
causation,  pathology,  and  symptoms  are  ex]>lainable  by  the  phenomena 
of  gout  exhibited  in  other  parts,  and,  again,  by  the  effects  of  anti-gout 
therapeusis. 

First,  an  examination  of  the  teeth  themselves.  Teeth  lost  through  the 
disease  whose  symptoms  and  clinical  history  have  been  given  present  the 
exterior  appearance  before  described.  Upon  section  enamel,  dentin,  and 
cementum  are  found  to  be  highly  organized.  The  pulp-chambers  are 
frequently  almost  obliterated,  even  without  external  evidences  of  abra- 
sion or  erosion.  Data  relative  to  the  condition  of  the  pulp  and  peri- 
cementum are  wanting,  although  from  the  degree  of  immobility  of  the 
teeth,  it  may  be  inferred  that  the  pericementum  is  markedly  diminished 
in  volume  prior  to  the  beginning  of  the  disease. 

A  tooth  lost  through  this  affection  has,  as  stated,  a  degree  of  root- 
denudation — pericemental  necrosis — governed  by  the  stage  of  disease 
at  which  the  tooth  was  extracted.  Calculi  found  in  the  neci^osed  area 
give  the  reaction  of  urates,  masked  by  the  presence  of  calcium-phos- 
phate deposits. 


484  DISEASES  OF  THE  PERICEMENTUM. 

Without  the  existence  of  any  of  the  local  causes  of  acute  perice- 
mentitis, the  symptoms  of  this  disease  arise ;  they  may  subside,  and 
leave  the  pericementum  permanently  crippled,  or  they  may  cause 
necrosis  of  more  or  less  tissue  and  then  subside.  The  same  tooth  is 
liable  to  succeeding  attacks  until  the  destruction  of  pericementum  is 
complete. 

Local  therapeusis  alleviates,  but  does  not  cure  the  condition.  In  its 
earliest  stages  anti-gout  therapeusis  aifords  marked  relief.  Are  these 
phenomena  explicable  by  the  pathogenesis  of  gout  ?  Acute  and  chronic 
gout  may  persist  for  years  in  joints  of  gouty  patients,  and  yet  the  peri- 
cementum escape ;  again,  the  dental  disease  may  exist  and  no  history 
of  gout,  hereditary  or  acquired,  be  elicited. 

Dental  hypersesthesia,  a  disposition  to  grind  the  teeth  at  night, 
shifting  of  positions  of  the  teeth,  and  abrasion  have  all  been  noted  as 
accompaniments  of  gout  by  Graves,  Duckworth,  Bartholow,  Garretson, 
and  others.  All  of  these  factors  admit  of  explanation  upon  the  theory 
of  a  gouty  causation. 

First,  as  to  the  character  of  the  teeth.  The  high  degree  of  organi- 
zation of  the  teeth — i.  e.,  the  formation  of  intercellular  substance,  formed 
matter  of  dentin — is  explained  upon  the  hypothesis  of  it  being  similar 
to  sclerotic  changes  in  other  connective  tissues.  It  is  inferred  that 
the  soft  tissues  of  the  pulp  and  the  pericementum  are  also  involved 
in  the  process  which  leads  to  an  increase  of  their  fibrous  elements. 
Doubtless,  also,  these  changes  involve  the  bloodvessels  of  these  struc- 
tures, lessening  their  calibre  and  their  elasticity.  This  would  represent 
the  primary  irritative  stage  of  the  uric-acid  dyscrasia.  Another  expres- 
sion of  the  irritative  stage,  altered  glandular  secretion,  has  been  dis- 
cussed under  the  head  of  erosion. 

Why  should  gout  attack  the  teeth  (the  pericementum)  of  some 
persons,  and  not  those  of  others  ?  and  Why  should  it  attack  some  teeth 
in  preference  to  others  ?  It  must  be  remembered  that  the  pericementum 
is  anatomically  a  ligament  as  well  as  a  periosteum,  and  that  the  union 
of  a  tooth  with  its  alveolus  is  a  joint.  It  is  attacked  for  the  same 
reason  that  any  joint  may  be  attacked  :  because  it  happens  to  be  a 
weak  articulation.  The  probable  explanation  of  the  selective  action 
of  gout-poison  for  the  metatarso-phalangeal  articulation  is  because  this 
joint  normally,  in  walking  and  standing,  does  a  great  deal  of  work, 
receives  a  blow  and  pressure  with  every  step,  and  therefore  would 
suifer  early  from  disuse,  according  to  a  general  physiological  law.  If 
it  is  not  vigorously  used,  and  it  is  not,  in  many  gouty  patients,  its  nutri- 
tion is  disturbed  and  its  vascular  currents  become  sluggish.  Analogous 
conditions  may  be  established  in  the  dental  ligament,  the  pericementum. 
Owing   to    an    increase    in   its  tenuity  and  a  decrease  of  its  vascular 


GOUTY  PERICEMENTITIS.  485 

supply,  its  nutritive  exchanges — its  currents — become  sluggish.  If  the 
teeth  be  used  vigorously,  the  sluggish  circulation  may  be  partially  coun- 
terbalanced ;  if"  not,  vascular  sluggishness  is  increased  and  a  further 
predisposition  to  degenerations  is  established.  Lack  of  mastication,  a 
common  failing  in  nearly  all  persons,  is  very  common  among  gouty 
persons,  particularly  excessive  eaters,  who  usually  take  food  requiring 
little  mastication.  It  is  among  this  class  of  persons  that  gingivitis, 
accompanied  by  subgingival  calculi,  is  common,  producing  the  first 
variety  of  pyorrhea,  which  may  complicate  or  be  aggravated  by  the 
local  action  of  tlie  gout-poison.  The  conditions  of  debility  resulting 
from  disuse  of  a  structure  exhibiting  incipient  degenerations,  need  but 
slight  exciting  causes  to  give  rise  to  acute  disease.  The  wedging  of 
teeth,  chance  blows,  and,  among  women,  thread-biting,  may  determine 
an  injury  to  the  pericementum  sufficient  to  make  it  the  weak  joint  in 
which  the  gout-poison  settles.  In  many  cases  a  slight  mal-occlusion 
may  be  the  medium  of  injury  to  the  dental  articulation.  This  is  most 
notable  in  those  cases  where  chronic  constructive  changes  in  the  peri- 
cementum have  caused  a  thickening  of  some  portion  of  the  alveolar 
process  between  two  teeth,  causing  the  teeth  to  shift  their  position,  and 
giving  rise  to  the  condition  termed  by  Duckworth  the  "buck  teeth"  of 
gout.  The  teeth  are  brought  into  mal-occlusion,  which  determines  the 
point  of  attack — the  point  of  least  resistance.  These  causes,  both  pre- 
disposing and  exciting,  may  not  be  in  evidence,  in  which  event  the  teeth 
escape  attack. 

Given  the  predisposing  and  exciting  causes  Avhich  result  in  an  area 
of  lessened  resistance  in  a  portion  of  the  pericementum  of  some  tooth, 
when  an  excess  of  urates  in  the  circulating  fluids  occurs,  urates  are  de- 
posited in  the  area  of  pericemental  irritation  ;  necrosis  of  the  injured 
tissue,  the  seat  of  the  deposit,  occurs.  Whether  the  deposit  precedes 
necrosis,  or  the  necrosis  precedes  the  deposit,  as  originally  set  forth  by 
Ebstein,  is  not  known  :  an  acid  reaction  is  established  which  causes  pre- 
cipitation of  urates.  Inflammation  is  excited  in  the  neighboring  por- 
tions of  the  pericementum,  which  breaks  down,  as  does  also  the  adjacent 
alveolar  process.  An  outlined  or  general  swelling  occurs,  which  may 
subside,  or,  if  the  inflammation  persist,  a  discharge  of  glairy,  mucus- 
like material  may  occur  at  the  neck  of  the  tooth,  or  in  some  cases  pus 
— gouty  abscess — discharges.  The  discharge  may  occur  through  the 
gum  over  the  site  of  a  circumscribed  alveolar  loss.  As  the  gum-attach- 
ment is  unbroken  before  the  period  of  discharge,  infection  of  the  part  has 
presumably  occurred  in  the  same  manner  as  it  occurs  in  cases  of  pulp- 
death  without  caries.  The  original  uratic  deposit  afterward  becomes  ob- 
scured by  deposits  of  the  calculi  which  occur  in  continued  pus-formation. 
These  act  as  continuous  irritants,  so  that  the  remainder  of  the  periceraen- 


486  DISEASES  OF  THE  PERICEMENTUM. 

turn  and  alveolar  wall  degenerates  and  disappears  molecularly.  In  the 
absence  of  pus-formation  the  uratic  deposits  may  be  covered  in  or  mixed 
with  light  phosphatic  concretions,  as  in  common  tophi.  In  the  ab- 
sence of  an  apparent  exciting  cause  for  the  location  of  the  attack,  it  is 
presumed  that  the  changes  in  the  vessels  have  proceeded  farther  in 
some  portion  of  the  pericementum  of  one  tooth  than  in  others ;  the  de- 
bility is  most  pronounced  there  in  consequence. 

The  general  pulpal  hyperaesthesia  noted  in  connection  with  the  earli- 
est stages  of  the  disorder,  may  be  attributed  to  the  presence  in  the  periph- 
eral circulation  of  irritating  material.  The  same  explanation  applies 
to  the  occurrence  of  attacks  of  pericemental  hyperaesthesia,  in  which 
there  is  a  disposition  to  grit  the  teeth.  It  will  be  observed  that  in  both 
of  these  states  there  is  early  active  hypersemia  of  the  parts.  It  is  pre- 
sumed that  this  is  the  antecedent  and  the  cause  of  sclerotic  changes 
which  cause  increased  dentinal  formation  and  increased  density  of  alve- 
olar walls,  attended  by  increased  tenuity  of  the  pericementum. 

Prognosis. — The  prognosis  of  the  disease  depends  largely  upon  the 
form  in  which  it  first  exhibits  itself,  and  also  upon  the  length  of  time 
an  increased  amount  of  waste-products  has  been  present  in  the  circulation. 
In  all  grades  of  the  inflammation,  except  that  attended  by  pus-forma- 
tion, the  cure  of  the  general  condition  is  usually  followed  by  a  more  or 
less  prompt  subsidence  of  the  dental  symptoms,  although  if  a  tooth  be 
loose,  the  condition  may  improve,  but  does  not  disappear.  If  pus  form, 
as  indicated  by  the  unusual  activity  of  the  inflammatory  symptoms, 
destruction  of  tissue,  pericemental  and  alveolar,  it  will  progress  until  it 
is  given  vent,  no  matter  how  active  or  efiective  in  other  particulars  anti- 
gout  therapeusis  may  be.  In  these  cases  the  tooth  is  usually  lost  sooner 
or  later. 

One  or  more  teeth  may  be  repeatedly  attacked,  and  if  the  underlying 
cause  be  promptly  removed,  they  may  partially  recover. 

Because  one  tooth  of  a  denture  is  afi'ected  it  does  not  necessarily  fol- 
low that  others  will  become  affected ;  a  single  tooth,  or  two  teeth,  may 
represent  the  weak  articulations  or  points  of  selection  of  the  gout- 
poison,  and  others  remaining  unaifected.  It  is  usual,  however,  if  the 
gouty  condition  be  not  held  in  abeyance,  for  successive  teeth  to  become 
affected. 

Treatment. — The  treatment  is  both  general  and  local ;  the  import- 
ance of  general  therapeutics  outweighing  that  of  local  measures  of  treat- 
ment. 

The  local  treatment  will  depend  upon  the  local  conditions  present. 
Some  of  these  may  be  similar  to  those  noted  in  connection  with  the 
previously  described  varieties  of  pyorrhoea — looseness  of  the  teeth, 
mal-occlusion,  infection,  the  presence  of  dead  and  foreign  material,  etc. 


GOUTY  PERICEMENTITIS.  487 

Each  of  these  conditions  requires  correction  by  means  already  described. 
As  reo:ards  tlie  peculiar  mode  of  infection  and  some  of  the  anatomical 
conditions,  the  treatment  in  many  respects  is  similar  to  that  of  phage- 
denic pericementitis.  The  site  of  actual  infection,  the  situation  of 
calculi  and  of  dead  tissue,  the  degenerating  alveolar  edges,  and  the 
unbroken  gingival  margin  are  similar,  except  that  in  the  gouty  cases  the 
gingival  attachment  may  be  intact.  It  is  even  more  important  then 
in  such  cases  that  entrance  to  the  area  of  necrosis  be  made  through  a 
special  opening.  A  semicircular  flap,  as  described  in  connection  with 
the  treatment  of  phagedenic  pericementitis,  should 
be  raised  and  the  disease-area  explored  and  freely 
scraped  to  free  it  from  all  dead  and  dying  tissue. 
The  pockets  should  be  syringed  with  hydrogen 
dioxid  solution  and  touched  with  an  antiseptic 
stimulant  preparation  ;  any  of  those  previously 
given  will  answer  (Fig.  377).  The  flap  should  next 
be  stitched  into  place.  An  antiseptic  mouth-wash 
should  then  be  prescribed.  In  pyogenic  cases  find- 
ino;  vent  at  the  gum-margin  the  treatment  should 

,    ''.  T         •      1       •   1      1  o     ^  1       •  •  .   •  ^.calculus. 

be  identical  with  that  oi  phagedenic  pericementitis. 

If  the  existing  constitutional  disorder  do  not  receive  correction,  all 
local  measures  of  treatment  will  be  of  but  slight  avail ;  not  only  may 
the  disease  appear  upon  other  teeth,  but  the  regenerative  processes  about 
the  teeth  which  receive  local  treatment  Avill  entirely  fail. 

The  treatment  of  the  general  condition  concerns  the  general  prac- 
titioner more  than  the  dentist,  but  there  are  frequently  attendant  cir- 
cumstances in  these  cases  which  render  it  not  only  advisable  but  impera- 
tive that  the  dentist  should  furnish  direction  as  to  diet  and  ]H'escribe 
medicinally. 

In  many  cases  the  evidence  of  a  gouty  condition,  aside  from  the 
dental  disease — and  this  is  also  true  of  dental  erosion — are  so  faint  that 
general  practitioners,  even  if  advised  of  the  probable  existence  of 
masked  or  obscure  gout,  refuse  to  be  guided  by  the  indications  pointed  out 
and  the  diagnosis  made  by  the  dental  practitioner.  These  dental  signs 
will,  no  doubt,  in  the  near  future,  come  to  be  regarded  by  the  general 
practitioner  as  valuable  diagnostic  indications  of  the  existence  of 
obscure  gout ;  the  evidences  of  dental  induration,  the  existence  of 
dental  erosion,  or  the  occurrence  of  pericemental  degenerations,  will  all 
be  regarded  as  pointing  to  the  existence  of  some  gouty  disorder. 

The  general  therapeutics  of  gout  embraces  medicinal  agents  and 
regulation  of  diet,  the  elimination  of  the  gout-poison  and  the  preven- 
tion of  its  formation.  The  principle  of  general  therapeusis  applied  in 
the  treatment  of  goutv  conditions  is  diuresis.     All  agents  which  increase 


488  DISEASES  OF  THE  PERICEMENTUM. 

secretion  of  urine  have  a  beneficial  eifect.  The  ingestion  of  large 
quantities  of  water  raises  the  blood-pressure  and  flushes  the  tissues  of 
the  body  and  the  kidneys ;  hence  elimination  of  formed  waste-products 
is  increased.  If  the  water  (as  many  "  mineral  waters  ")  contains  salts 
of  potassium,  the  diuretic  eifect  is  increased.  Solutions  of  potassium 
bitartrate  (acid  tartrate  of  potassium)  are  in  general  use  for  this  purpose, 
forming  the  basis  of  many  "  fever  mixtures/'  whose  object  is  to  rid  the 
body  of  the  products  of  nitrogenous  waste.  The  citrates,  tartrates,  and 
acetates  of  potassium,  sodium,  and  lithium,  all  neutral  salts,  when  taken 
into  the  circulation  are  converted  in  the  tissues  into  alkaline  salts — 
carbonates — which  render  the  urine  alkaline,  if  present  in  sufficient 
amount,  and  increase  excretion,  provided  they  be  taken  in  large 
volumes  of  water. 

The  danger  from  the  presence  of  urates  consists  in  the  excessive 
formation  of  acid  urates,  the  solubility  of  which  is  low.  If  converted 
into  neutral  urates,  their  solubility  is  increased  and  the  tendency  to  de- 
position is  correspondingly  diminished.  Upon  this  fact  depends  the 
efficacy  of  salts  of  lithium  in  conditions  of  gout.  Taken  into  the  cir- 
culation, neutral  lithium  urate  is  formed  from  the  acid  urates,  an 
increased  volume  of  which  can  be  held  in  solution  by  the  circulating 
fluids,  the  tendency  to  deposition  being  lessened.  If  the  lithium  salt 
be  taken  with  free  draughts  of  water,  there  is  the  additional  factor 
of  free  diuresis.  E.  C.  Kirk  has  introduced  the  bitartrate  of  lithium 
as  a  substitute  for  the  citrate  usually  employed  ;  its  solvent  power  is 
greater  and  it  has  a  specific  diuretic  action. 

Increase  of  the  alkalinity  of  the  blood  and  the  induction  of  free 
diuresis  are  the  objects  sought.  It  is  by  reason  of  their  eliminant 
action  that  preparations  of  colchicum  act  as  curative  agents  in  acute 
gouty  inflammations. 

Piperazin  (C4Hi|,N2,  diethylene-diamin)  is  said  to  possess  twelve 
times  the  solvent  power  for  uric  acid  that  lithium  carbonate  has.  Hare,' 
however,  failed  to  obtain  any  beneficial  effects  from  the  use  of  this  drug 
in  gout.     Stewart  ^  has  recorded  ill  cerebral  effects  from  its  use. 

The  salicylate  of  sodium  is  commonly  used  in  gouty  affections  as  a 
uric-acid  eliminant,^  but  more  particularly  to  relieve  attendant  pains. 

As  the  cases  of  acute  gouty  affections  are  usually  readily  recognized 
and  treated  by  the  general  practitioner,  the  advice  of  the  dental  prac- 
titioner applies  only  in  cases  without  classical  symptoms ;  his  recom- 
mendations, therefore,  need  scarcely  exceed  advising  the  free  use  of 
water  containing  potassium  or  lithium  salts.  A  tablet  of  lithium 
bitartrate  dissolved  in  a  half  pint  or  more  of  water,  to  be  taken  three 
times  daily,  is  usually  sufficient  medicinal  treatment. 

1  Practical  Therapeutics.  ^  Ibid.  '^  Haig. 


GOUTY  PERICEMENTITIS.  489 

Advice  should  always  be  given  as  to  a  dietetic  course  which  will 
miuiniize  tlie  fbrraatit>u  of  urates  and  secure  elimination  of  the  waste 
formed. 

Measures  should  he  advised  to  increase  the  oxidizing  function. 
Free  exercise  in  the  open  air  is  of  first  importance,  and  is  only  second 
to  the  correction  of  anaemic  conditions ;  this,  however,  concerns  the 
general  practitioner,  as  it  involves  the  prescribing  of  a  course  of  iron  or 
arsenic.  Disorders  of  the  intestinal  tract  and  its  appendages,  par- 
ticularly hepatic  disorders,  also  demand  correction. 

The  diet  should  be  of  a  character  which  will  lessen  the  formation  of 
urates.  The  amount  of  vegetable  food,  in  proportion  to  animal,  should 
be  increased,  thus  raising  the  alkalinity  of  the  body-fluids.  Red  meats, 
and  white  meats  difficult  of  digestion,  increase  the  formation  of  urates. 
Poultry  and  shell-fish  in  the  dietary  lessen  the  formation  of  urates. 
The  consumption  of  malt  liquors  notably  increases  it,  and  sweet  wines, 
particularly  champagnes  (both  sweet  and  dry),  are  poisonous  to  gouty 
patients.  Spirituous  liquors  are  also  harmful,  since  they  lessen  tissue- 
oxidation  and  produce  gastric  and  hepatic  disturbances  which  cause 
faulty  metabolism. 

Recognizing  the  predisposition  which  exists  in  gouty  persons  to 
active  pericemental  degenerations,  the  operator  should  guard  against 
injuries  to  the  pericementum,  which  might  induce  a  weak  articulation  and 
precipitate  gouty  pericementitis.  Such  teeth  should  not  be  wedged  ; 
injury  to  the  gum  or  gum-margins,  by  the  use  of  improper  rubber-dam 
clamps,  ligatures  driven  beneath  margins,  etc.,  may  excite  the  first 
stages  of  a  degeneration  which  will  end  only  in  the  loss  of  the  abused 
tooth. 


SECTION  VI. 


CHAPTER   XXVII. 

DISEASES  OF  THE  DECIDUOUS  TEETH  AND  THEIR  TREAT- 
MENT. 

The  deciduous  teeth  are  subject  to  several  diseases  which  affect  the 
permanent  teeth.  Their  crowns  may  be  the  seat  of  deposits — rarely, 
however,  of  salivary  calculi.  They  may  be  affected  by  mechanical 
abrasion,  dental  caries,  and  acute  diseases  of  the  pulp,  pericementum, 
and  alveolar  walls.  In  deciduous  teeth  septic  pericementitis  frequently 
runs  a  chronic  course,  but  other  chronic  degenerations  of  the  pericemen- 
tum are  rare,  except  in  connection  with  constitutional  diseases,  notably 
rachitis. 

Owing  to  peculiarities  of  structure  and  anatomical  associations, 
diseases  of  the  temporary  teeth  present  features  different  from  those  of 
the  same  diseases  occurring  in  the  teeth  of  adults.  The  dentin  of 
the  deciduous  teeth  appears  never  to  possess  the  high  degrees  of  sensi- 
tivity noted  in  the  adult  teeth  of  some  persons.  In  acute  affections  of 
the  pulp  the  pains  have  less  of  a  reflex  character,  being  confined  to  the 
dental  region  ;  nor,  so  far  as  subjective  phenomena  are  observed,  are 
these  pulp-pains  of  such  severity  as  in  adult  teeth.  The  lymphatic  con- 
nections of  the  deciduous  teeth  appear  to  be  more  free  than  those  of  the 
permanent  teeth,  so  that  involvement  of  the  lymphatic  glands — i.  e., 
evidence  of  septic  absorption — is  more  frequently  observed  in  connec- 
tion Avith  diseases  of  the  deciduous  than  with  those  of  the  permanent 
teeth. 

Acute  catarrhal  inflammations,  including  several  forms  of  ulcerative 
action,  belong  so  distinctively  to  the  period  during  which  the  temporary 
teeth  are  in  position  that  they  are  classified  as  diseases  of  the  mouths  of 
children. 

All  therapeutic  measures,  medicinal  and  mechanical,  are  directed 
toward  insuring  the  non-septic  retention  of  these  teeth  for  a  period  of 
but  five  years,  so  that  they  may  be  and  frequently  are  of  a  type  differ- 
ing from  those  directed  toward  the  retention  of  dental  organs  for  a  life- 
time ;  moreover,  they  are  modified  by  peculiarities  of  anatomical  rela- 
tionships. 

Loss  of  the  deciduous  teeth  through  other  than  physiological  pro- 

491 


492  DISEASES  OF  THE  DECIDUOUS  TEETH. 

cesses  should  not  be  regarded  with  unconcern,  for  while  it  is  true  that 
pyogenic  processes  may  exist  for  a  long  period  upon  the  roots  of  a  tem- 
porary tooth,  its  permanent  successor  underlying  it  being,  at  least  so 
far  as  outward  form  is  concerned,  unaffected,  it  is  more  than  probable 
that  it  is  affected  in  its  deeper  histological  structure  and  anatomical 
organization.  The  effects  of  too  long  retention  and  too  early  extraction 
of  the  deciduous  teeth  have  been  already  discussed  under  the  head  of 
malpositions  of  the  teeth. 

Deposits  upon  the  Teeth. 

The  deposits  upon  the  deciduous  teeth  are  usually  confined  to  the 
cervical  portion  of  the  labial  and  buccal  enamel,  appearing  as  creseentic 
lines  of  green  stain.  These  deposits,  together  with  white  deposits  of 
debris  in  the  gingivo-dental  depression,  are  most  frequently  observed 
in  the  mouths  of  children  whose  teeth  receive  little  or  no  care.  They 
are  probably  due  to  the  growth  of  chromogenic  fungi  in  the  remains 
of  the  enamel-cuticle,  which  persists  longer  in  this  situation  than  in  any 
other.  The  only  clinical  significance,  or  rather  pathological  significance, 
of  these  deposits,  is  that  they  appear  to  furnish  a  predisposition  to  dif- 
fuse and  ulcerative  stomatitis  ;  the  connection  between  the  two  is  by  no 
means  clear,  although  the  association  is  frequent. 

Such  deposits  are  to  be  removed  as  described  in  Chapter  XXIV.  This 
trifling  operation,  as  well  as  those  of  greater  extent  upon  the  deciduous 
teeth,  is  attended  by  difficulties  absent  in  operations  upon  the  teeth  of 
adults.  Children  may  be  presented  for  dental  treatment  as  early  as 
the  third  or  fourth  year.  At  this  age  they  are  too  young  to  appreciate 
the  importance  of  dental  service,  or  to  be  reasoned  with  ;  difficulties 
which  are  still  further  increased  by  insubordination,  frequently  abetted 
rather  than  curbed  by  the  child's  guardian.  Children  will  rarely  submit 
to  inconvenience,  much  less  to  any  degree  of  suffering  incidental  to  den- 
tal operations.  The  physical  character  of  the  infantile  mouth  furnishes 
additional  obstructions  :  the  entrance  to  the  mouth  is  small ;  the  mouth- 
cavity  is  shallow  owing  to  the  shortness  of  the  teeth  and  the  alveolar 
process ;  and  the  salivary  secretion  is  very  free  ;  thus  dryness  of  the 
parts,  one  of  the  most  efficient  aids  to  accurate  and  painless  dental  ope- 
rations, is  but  imperfectly  attainable.  It  is  rare  that  the  rubber-dam 
can  be  used  before  the  sixth  or  seventh  year.  The  muscles  of  the  tongue 
and  lips  of  children  are  singularly  uncontrollable. 

Much  may  be  accomplished  with  children  through  tact  upon  the  part 
of  the  operator.  Until  the  child  has  become  familiarized  with  the 
dental  chair,  and  with  having  its  mouth  examined,  teeth  touched, 
pressed  upon,  etc.,  operations  should  be  confined  to  trifling  procedures 
occupying   but    few  minutes  at    most.     The    growing  familiarity  will 


ABRASION  OF  THE  DECIDUOUS  TEETH.  493 

secure  quiet  of  the  patieut,  the  most  essential  })relimiiuiiy  to  operating. 
Lack  of  patience,  or  tlie  use  of  force  upon  the  part  of  the  operator, 
is,  exccipt  in  rare  cases,  an  eflPei^tual  bar  to  present  or  any  future  opera- 
tions. Many  children  may  be  given  a  ])ermanent  dread  of  dentists  and 
dental  operations  by  some  ill-considered  move  upon  the  i)art  of  the 
operator. 

Even  premising  quiet  of  the  patient,  the  form  of  the  mouth,  lack 
of  dryness,  and  necessity  for  short  sittings  make  operations  on  the 
deciduous  teeth  a  compromise  between  what  should  be  done  and  what 
can  be  done. 

It  is  quite  as  important  that  the  temporary  masticating  apjiaratus 
should  be  kept  in  full  working  condition  as  it  is  for  the  permanent.  As 
em})hasized  by  Guilford,^  during  the  period  that  the  deciduous  teeth  are 
in  position  the  alimentary  canal  and  its  glandular  appendages  are  still  in  a 
developmental  stage,  and  any  disturbance  of  oral  physiology,  resulting  in 
the  stomach  receiving  poorly  masticated  food-stuffs,  may  react  upon  its 
normal  development.  Such  cases  may  at  least  induce  functional  gastro- 
intestinal disturbances  of  some  gravity.  The  existence  of  painful  dis- 
eases of  the  teeth  materially  hinders  mastication,  so  that  their  correction 
is  demanded  to  relieve  ])ain  and  to  restore  the  partially  lost  function. 

Abrasion  of  the  Deciduous  Teeth. 

The  occlusal  surfaces  of  the  deciduous  teeth  may  wear  away  to  a  great 
extent.  In  some  cases,  this  appears  to  be  due  to  active  fermentative 
changes  in  the  mouth,  which  cause  a  general  acid  reaction  of  the  fluid 
contents  of  the  mouth  ;  owing  to  faulty  organization  of  the  cusp-enamel, 
it  may  be  readily  soluble,  and  the  teeth  may  be  worn  down  and  abraded 
through  the  combined  action  of  solvents  and  the  mechanical  abrasion 
of  mastication. 

The  cases  of  this  condition  observed,  while  associated  with  the 
presence  of  dental  caries  in  some  of  the  teeth,  showed  an  exemption 
from  caries  in  the  teeth  most  abraded — those  which  were  washed  clean. 
More  than  this,  in  some  of  the  teeth,  worn  nearly  to  the  gum-margin, 
evidences  of  secondary  constructive  action  upon  the  part  of  the  pulp 
appeared  ;  the  teeth  were  worn  beyond  the  original  limits  of  the  pulp- 
chamber  and  the  pulps  were  still  vital. 

Another  form  of  abrasion  may  be  seen  in  teeth  whose  tissue-organ- 
ization is  not  faulty.  Children  whose  rectums  are  infested  with 
parasites,  as  the  ascaris  lumbricoides,  taenia  (taj)eworm),  etc.,  and  who 
suffer  from  irritable  bladder  due  to  hyperacidity  of  the  urine,  com- 
monly have  a  reflex  stimulation  of  the  muscles  of  mastication  during 

^  Proc.  Academy  of  Stomatology,  1896. 


494  DISEASES  OF  THE  DECIDUOUS  TEETH. 

sleep,  which  causes  the  forcible  grinding  of  the  teeth.  The  enamel 
of  the  teeth  may  be  worn  down  and  abraded,  as  observed  in  adults. 

Treatment. — The  treatment  of  abraded  surfaces  M'here  the  dentin  is 
exposed  is  to  wash  the  mouth  with  an  antiseptic,  not  one  containing 
chlorids,  but  hvdrog-en  dioxid.  Drv  the  dentin-surfaces  and  rub  them 
vigorously  with  fused  silver  nitrate.  This  silver  salt,  rubbed  upon  dentin, 
forms  with  its  organic  constituents  an  albuminate  of  silver,  which  is 
persistently  antiseptic.  Under  the  influence  of  light  it  is  reduced  to  the 
oxid  of  silver,  which  is  slowly  converted  into  silver  lactate  through  the 
lactic  acid  produced  in  the  mouth.  Silver  lactate,  as  contemporary 
surgical  practice  tcBtifies,  is  a  most  efficient  antiseptic.  Contrary  to 
previously  held  opinions,  Truman's  experiments  ^  indicate  that  silver 
nitrate  is  a  very  penetrating  coagulant,  so  that  the  reactions  above  given 
persist  for  a  long  period.  It  is  in  consequence  of  these  peculiarities 
that  silver  nitrate  is  found  so  effective  in  checking  and  preventing 
dental  caries. 

The  continued  use  of  antiseptic  mouth-washes  is  advised.  Listerine, 
to  which  a  minute  portion  of  saccharin  has  been  added  to  sweeten  it, 
diluted  one-half,  is  an  agreeable  antiseptic  for  continued  use. 

In  cases  of  grinding  of  the  teeth,  the  source  of  the  reflex  disturbance 
should  be  removed  by  the  general  practitioner.  Belladonna,  which  chil- 
dren stand  well  relatively  large  doses  of,  is  the  medicinal  agent  most 
used  to  lessen  vesical  irritability.  The  urine,  however,  must  have  its 
acidity  lessened  through  an  increased  vegetable  diet,  and,  if  required, 
potassium  salts.  Rectal  parasites  should  be  removed  through  the  use 
of  vermifuges — santonin,  male  fern,  or  others,  depending  upon  which 
parasite  is  present.  Small  seat-worms,  causing  pruritus,  may  be 
destroyed  by  rectal  injections  of  weak  solutions  of  phenol  sodique, 
a  teaspoonful  in  a  half  pint  of  water. 

Caeies  of  the  Deciduous  Teeth. 

Unless  constant  supervision  of  the  deciduous  teeth  be  exercised, 
caries  is  very  liable  to  progress  to  the  extent  of  pulp-exposure  without 
the  previous  warning  sign — dentinal  sensitivity. 

While  the  canal-portions  of  the  pulps  of  these  teeth  are  frequently 
fine,  flattened,  and  tortuous,  the  pulp-chamber  has  a  relatively  large  size, 
so  that  pulp-exposure  follows  quickly  upon  loss  of  a  section  of  enamel. 
Eternal  vigilance  is  the  price  of  pulp-salvation  in  the  deciduous  teeth. 

The  approximal  surfaces  of  the  deciduous  teeth  appear  to  be  more 

quickly  and  generally  affected  than  the  occlusal  surfaces.     Again,  the 

occlusal  surfaces  of  the  second  molars  are  more  frequently  affected  than 

those  of  the  first  molars.     The  anatomical  forms  and  arrangement  of 

^  Proc.  Academy  of  Stomatology,  1895. 


CARIES  OF  THE  DECIDUOUS  TEETH.  495 

the  teeth  explain  these  conditions  ;  the  approximal  surfaces  particularly 
of  the  molars,  and  the  occlusal  surfaces  of  the  second  molars,  aiford 
lodgement  for  food-debris  more  readily  than  do  other  situations. 

It  is  rare  that  decided  pain,  increased  by  applications  of  cold  or 
heat,  and  excited  by  the  presence  of  sugar  in  the  mouth,  occurs  before 
actual  exposure  of  the  pulp.  In  a  majority  of  the  cases  which  present 
themselves  throbbing  pain,  indicative  of  pulpitis,  is  present. 

If  cavities  are  observed  before  pain  has  been  complained  of,  and 
prompt  and  quickly  subsiding  response  to  applications  of  cold  water 
is  obtained,  indicating  a  normal  pulp,  the  cavity  should  be  excavated, 
with  more  regard  to  removing  the  marginal  caries  than  to  thorough  ex- 
cavation, and  an  application  of  hydrogen  dioxid  made.  The  dentin  is 
dried,  and  an  application  of  a  20  per  cent,  solution  of  silver  nitrate  is 
made  for  a  few  minutes,  the  cavity  being  subsequently  filled. 

In  cases  of  adjoining  approximal  cavities  there  is  a  disposition  for  the 
aifected  teeth  to  press  together  and  lessen  the  size  of  the  dental  arch. 
Bonwill  advises  as  a  practice,  followed  by  uniformly  good  results  in 
such  cases,  to  cleanse  the  cavities  (Fig.  378)  and  insert  masses  of  pink 
gutta-percha  base-plate.  The  constant  biting  upon  the 
gutta-percha  causes  a  separation  of  the  teeth  which  in-  Fig^8. 
creases  the  size  of  the  arch  and  affords  additional  space 
for  permanent  successors.  He  advises  that  before  the 
gutta-percha  masses  are  inserted  that  small  pieces  of 
blotting-paper  saturated  with  carbolic  acid  be  laid 
against  the  dentinal  walls  and  the  gutta-percha  be 
packed  over  them.     The  more  efficient  and  persistent    '^^"^^  '^^  preparing 

.  ..,  .  ,  ,.,.  1  approximal  cav- 

antiseptic  silver  nitrate  may  be  applied  instead  of  the      ities. 
carbolic  acid.     Kirk  advises  that  asbestos-felt  be  heated 
to  destroy  any  organic  matter  present  in  it  which  might  combine  with 
the  silver,  and  then  be  soaked  in  a  saturated  solution  of  silver  nitrate, 
dried,  and  kept  in  dark  bottles  away  from  the  light.     Small  pieces  of 
the  prepared  felt  may  be  used  as  described. 

The  silver-nitrate  method  is  particularly  applicable  to  shallow  cavi- 
ties in  which  excavation  for  filling  is  impracticable.  The  dentin-surface 
is  cleansed  and  dried,  and  the  fused  silver  nitrate  is  rubbed  upon  the 
surface.  This  may  be  done  after  the  method  of  Craven  :  a  platinum 
wire  is  dipped  into  the  powdered  salt  and  held  over  a  flame  until  the 
powder  fuses  into  a  button.  By  this  means  applications  can  be  directly 
and  accurately  made. 

These  shallow  cavities  frequently  form  upon  the  distal  walls  of 
second  molars,  and  the  erupting  permanent  first  molar  crowds  into  the 
carious  area,  not  only  reducing  the  space  for  the  future  bicuspids,  but 
inducing  caries  in  the  mesial  wall  of  the  permanent  tooth,  and  permit- 


496  DISEASES  OF  THE  DECIDUOUS  TEETH. 

ting  the  deep  invasion  of,  and  pulp-destruction  in  the  temporary  tooth. 
If  these  cavities  can  be  given  a  retentive  form/  it  should  be  done,  and 
a  filling  having  an  exaggerated  and  rounded  contour  inserted,  against 
which  the  erupting  permanent  tooth  will  press  with  a  minimum  of  con- 
tact-area. In  case  of  non-retentive  form  a  disk  is  used  to  cut  away  the 
surface,  leaving  above  the  neck  of  the  tooth  a  shoulder-like  projection 
to  hold  back  the  permanent  tooth  (Fig.  379).  The  cut  surface  should 
be  treated  with  silver  nitrate. 

Diseases  of  the  Pulp. 

If  the  case  be  seen  at  a  stage  when  paroxysmal  pain  is  caused  by 
applications  of  cold,  indicating  active  hypersemia  of  the  pulp,  an  attempt 
should  by  all  means  be  made  to  soothe,  protect,  and  maintain  the  vitality 

of  the  pulp.     The  principal  object  in  maintain- 
ing vitality  of  the  pulp  is  that  the  physiological 
process  of  root-resorption  may  not  be  aborted, 
prevented,    or   deranged.     It    is   undoubtedly 
//  /f\\  \\  Vv...4\-----v\     true  that  root-resorption  does  occur  in  the  ab- 
■i-/J^''     ~%^Vi    '~--..,''  '•-—-''      sence  of  a  pulp,  if  the  roots   be  in  an  aseptic 
i'\        /  )  condition  f  but  in  the  absence  of  the  pulp  the 

''--::::::'--''  process  is  irregular  and  incomplete  (Fig.  380), 

'"ZS'"X  1  STa"!  ^-xJ  ""y  °«t  occur.  Again,  it  is  probable  that 
of  the  temporary  second  mo-  the  destruction  of  the  pulp  and  the  resulting 
imperfect  resorption  may  disturb  the  nutritive 
balance  in  the  developing  alveolar  structures  in  a  manner  at  present 
unknown.  The  obtundent  oils  are  of  essential  service  in  all  of  the 
pulp-disturbances  of  children.  The  oils  of  cloves  and  gaultheria  are 
well-known  domestic  remedies  for  the  toothache  of  children ;  thymol 
is  the  most  effective.  The  cavity  of  decay  is  syringed  with  tepid 
water  and  dried,  and  a  pellet  of  cotton  dipped  in  one  of  these  oils  is 
inserted.  The  cavity  is  given  a  retentive  form,  its  walls  painted  with 
a  non-conducting  varnish,  or,  what  is  better,  a  pulp-cap  filled  with  a 
paste  (thymol,  glycerin,  and  zinc  oxid)  is  laid  upon  the  deep  wall  of  the 
cavity  and  a  filling  of  zinc  phosphate  flowed  over  it. 

If  evidences  of  active  pulpitis — repeated  paroxysms  of  pain,  par- 
ticularly throbbing  pain — occur,  it  is  advisable  to  destroy  and  remove 
the  pulp.  If  soothed,  and  the  cavity  filled,  the  pulp  dies  and  decom- 
poses, and  septic  pericementitis  arises.  In  any  event,  the  pulp  is 
first  reduced  to  a  condition  of  quiet. 

As  to  the  means  of  destroying  the  pulp,  it  should  be  remembered  that 
pulp-exposure,  although  it  may  occur  at  a  very  early  age,  usually  occurs 

^  Woodward,  Proc.  Academy  of  Stomatology,  1896. 
^  Proc.  Academy  of  Stomatology,  1896. 


DISEASES  OF  THE  PULP.  497 

where  the  process  of  root-resorption  has  made  some  degree  of  advance ; 

hence  the  communication  between  the  pulp  and  apical  tissues  is  more  free 

than    when    the    constriction    of    the    apical 

foramen  existed.     It    is    evident,   therefore,  Fig.  380. 

that  the  devitalizing  agent  (arsenic)  must  be 

nsed  with    extreme  care,  and  in    minimum 

amount,    to    prevent    its    passage    into    the 

apical   circulation.      The  usual  concomitant 

of  the  specific  necrotic  effects  of  arsenic  upon     j_   root-resorption    of    puipiess 

adult    pulps— iugulation  of  the   pulp-circula-  tooth:    B.  normal  resorption; 

I       I         J    ts  11  yital  pulp. 

tion  at  the  apical  foramen — will  probably  not 

be  in  evidence  because  of  the  increased  size  of  the  foramen. 

The  usual  shapes  of  cavities  leading  to  pulp-exposure  in  temporary 
teeth  demand  that  extra  precautions  be  taken  to  prevent  the  escape 
of  arsenic  from  the  cavity  upon  the  gum  ;  .moreover,  that  most  useful 
adjunct,  the  rubber-dam,  may  not  be  applicable,  so  that  the  dryness  of 
the  cavity  is  imperfect.  For  these  reasons  the  arsenic  should  be  con- 
tained in  devitalizing  fibre.  The  amount  used  should  be  very  minute 
and  v.ell  diluted.  The  fibre  is  laid  upon  the  exposure  and  retained  by 
means  of  cotton  and  sandarac,  or  temporary  stopping.  If  the  evidences 
of  acute  pulp-disturbance  have  been  very  severe,  it  is  advisable  to  retain 
the  fibre  by  flowing  over  it  thin  zinc  phosphate  to  avoid  pressure.  The 
application  is  not  to  remain  more  than  twenty-four  hours,  and,  if  root- 
resorption  have  progressed,  for  not  more  than  twelve  hours.  After  this 
time  the  pulp-chamber  is  to  be  opened,  when  it  may  be  found  that  the 
pulp  has  still  a  slight  degree  of  sensitivity.  Goddard  '  advises  that  gly- 
cerole  of  tannin  be  then  sealed  in  the  cavity  for  a  week  to  tan  the  pulp. 

Other  means  have  been  suggested  and  employed  to  effect  pulp- 
destruction,  to  avoid  the  dangers  incident  to  the  use  of  arsenic.  Darby 
uses  with  success  a  paste  of  about  ^-^  gr.  of  cantharides  in  carbolic  acid. 
Dunbar^  states  that  aqua  ammonise  applied  to  a  pulp  will  effect  its 
destruction.  Tr.  iodin  has  been  advised  by  others.  Increasing  press- 
ure by  cotton  pellets  charged  with  oil  of  cloves  is  a  slow  method  of 
destroying  a  pulp.^ 

The  pulp  is  removed  as  from  the  adult  teeth,  any  living  filaments 
being  destroyed  by  a  drop  of  trichloracetic  acid.  Previous  to  opening 
the  canals  the  mouth  should  be  drenched  with  antiseptics,  and  the 
carious  cavity  be  repeatedly  washed  with  pyrozone.  Dryness  should 
be  maintained  as  well  as  possible,  and  the  rubber-dam  used  where- 
ever  it  can  be  applied.  The  cleansed  canals  are  filled  with  an 
antiseptic  oil,  dried,  and  filled  at  once.     Two  materials  offer  themselves 

^  American  Text-book  of  Operative  Dentistry. 

2  Quoted  by  Goddard,  Ibid.  '  Flagg. 

32 


498  DISEASES  OF  THE  DECIDUOUS  TEETH. 

for  this  purpose  in  preference  to  all  others — melted  paraffin  and  balsamo 
del  deserto.  The  paraffin  may  be  combined  with  one  of  the  iodin 
preparations,  iodoform,  aristol,  or  nosophen. 

Septic  Pericementitis. 

Septic  pericementitis  presents  itself  as  an  acute  or  a  chronic  condi- 
tion following  upon  death  and  putrescence  of  the  pulp.  It  may  arise 
in  open  cavities,  or  under  fillings  which  were  placed  over  dying 
pulps. 

Its  symptoms  are  those  of  septic  apical  pericementitis  :  the  swelling 
is  pronounced ;  pain  is  not  so  severe  as  in  adult  teeth,  the  tooth  be- 
comes very  loose,  and  the  duration  of  the  disease  is  shorter  than  in  the 
adult.     The  general  symptoms,  however,  are  fre- 
^^"       ■  quently  much  more  pronounced  than  in  the  adult ; 

the  inflammation  may  be  attended  by  a  chill,  and 
frequently  by  a  pronounced  fever ;  the  neighbor- 
ing lymphatic  glands  may  in  a  few  hours  exhibit 
evidence  of  the  presence  of  septic  matter  in  them, 
by  swelling  and  tenderness.  The  point  of  exit 
of  the  pus  is  usually  directly  over  the  affected  root, 
and  not  very  far  from  the  gum-margin  (Fig.  381). 
Showing  the  relations  of  If  pus-cxit  be  delayed,  there  is  frequently  a  dispo- 
an  abscess  upon  a  tern-    gition  to  a  strippiup;  of  the  outcr  alveolar  perios- 

porary   tooth   with   the  ...  .  .  . 

crown  of  a  developing    tcum.    This,  in  Connection  with  wide  spreading  of 
permanent  tooth  under-    ^j^g  inflammation,  is  marked  and  common  in  stru- 

lying  it.  _  ' 

mous  children. 

Treatment. — The  treatment  consists  in  immediate  evacuation  of  the 
pus  and  washing  out  the  infected  tract  with  antiseptics.  The  patient's 
head  is  steadied  with  the  left  hand,  which  also  prevents  the  child  seeing 
the  bistoury.  The  last  fingers  are  rested  upon  the  teeth  to  prevent  slip- 
ping of  the  knife  through  movement  of  the  head  of  the  child,  and  a 
direct  cut  is  made  to  the  process.  The  nozzle  of  a  syringe  charged  with 
pyrozone  is  passed  into  the  tooth-cavity  and  the  fluid  is  driven  through 
the  abscess-tract.  This  is  to  be  repeated  until  bubbling  ceases.  The 
cavity  of  decay  is  sealed  after  placing  in  it  a  pellet  of  cotton  saturated 
with  2  per  cent,  formalin  solution  or  similar  disinfectant. 

As  .'^oon  as  acute  symptoms  have  subsided,  an  examination  of  the 
canals  should  l)e  made  to  determine  the  amount  of  root-resorption.  If  this 
have  progressed  far,  it  will  preclude  the  use  of  the  more  powerful  germ- 
icides used  in  canal-cleansing.  In  any  event,  strong  sodium  dioxid  can  be 
used  in  the  pulp-chamber,  but  its  introduction  into  the  canals  must  be 
guarded.  Sterilization  is  effected  there,  by  repeated  washings  with 
hydrogen  dioxid  or  meditrina,  followed  by  drying  the  canals  and  filling 


SEPTIC  PERICEMENTITIS.  499 

them  with  cotton  and  an  anti^^eptic  oil — thyme  or  cassia — to  test  the 
thoroughness  of  disinfection.  If  the  fistuhi  heal  and  the  tooth  be- 
comes  tight,  and  the  cotton  when  removed  from  the  root  has  no  odor 
of  putrefaction,  the  canals  should  be  filled  with  paraffin  and  aristol,  or 
balsamo  del  deserto.  In  cases  of  high  fever,  where  immediate  access 
cannot  be  gained  to  the  root-canals  for  disinfection,  the  immediate 
extraction  of  the  tooth  may  be  necessary. 

The  treatment  of  chronic  abscess  is  similar  to  that  of  the  acute 
variety  after  active  inflammation  has  subsided.  A  longer  time,  how- 
ever, is  required  for  sterilization,  as  the  dentin  of  the  root  is  usually 
badly  contaminated  by  noxious  material  and  the  soft  tissues  are  in  a 
state  of  debility,  a  condition  identical  with  chronic  infective  ulcer. 
Sodium  dioxid  may  be  used  with  comparative  freedom  in  these  cases,  as 
the  passage  of  a  small  amount  of  the  solution  acts  as  a  caustic  to  the 
diseased  tissues  beneath.  Campho-phenique  may  be  pumped  into  the 
canals  of  such  cases  without  fear  of  ill-results. 

If  inflammatory  symptoms  run  high,  particularly  in  debilitated 
children,  before  root-resorption  has  progressed  to  any  considerable 
extent,  limited  alveolar  necrosis  may  occur,  and  a  sequestrum  be 
formed,  which  will  require  removal.  In  such  cases,  however,  the 
tooth  need  not  be  extracted,  if  the  sepsis  can  be  controlled  and  the 
tooth  be  not  markedlv  loose. 


CHAPTER   XXVIII. 
REFLEX  DISORDERS  OF  DENTAL  ORIGIN. 

Recognizing  pain  as  a  condition  produced  through  the  overexcita- 
tion of  sensory  nerves,  a  reflex  pain  may  be  defined  as  a  pain  referred  to 
some  point  other  than  that  of  its  origin.  Pain  referred  to  the  distribu- 
tion of  a  sensory  nerve  may  be  due  to  overexcitation  of  any  portion  of 
the  nerve ;  in  its  terminal  distribution  ;  to  diseases  aifecting  any  portion 
of  the  nerve-trunk,  or  to  disorders  aifecting  the  central  termination  of 
the  nerve.  Again,  irritation  of  one  sensory  nerve  may  be  referred  to 
some  other  sensory  nerve.     The  condition  is  called  neuralgia. 

As  both  the  upper  and  the  lower  teeth  and  their  surroundings 
receive  their  neural  supply  from  branches  of  the  fifth  pair  of  cranial 
nerves,  discussion  of  this  subject  is  confined  to  causes  operating  within 
the  distribution  of  that  nerve. 

As  such  general  conditions  as  malaria,  syphilis,  and  forms  of  ansemia, 
operate  to  produce  neuralgia  which  may  be  referred  to  the  teeth,  or  the 
parts  about  them,  only  those  cases  will  be  regarded  as  dental  which 
have  undoubtedly  a  dental  origin,  as  evidenced  by  disappearance  of 
the  neuralgia  following  cure  of  the  exciting  dental  condition.  It  should 
be  noted,  however,  that  vague  and  sometimes  severe  pains  referred 
to  the  teeth  may  entirely  disappear  after  the  cure  of  some  constitu- 
tional disorder.  For  example,  cases  of  periodically  recurring  dental 
pain  have  been  entirely  relieved  through  the  administration  of  quinin 
and  arsenic ;  the  pains  were  clearly  of  malarial  origin.  Pain  about  the 
teeth  in  syphilitics  has  disappeared  after  the  administration  of  iodids. 
Pain  referred  to  the  teeth  in  anaemic  patients  has  disappeared  after  a 
long  course  of  chalybeates. 

Reflexes  of  dental  origin  are  both  motor  and  sensory,  the  latter  far 
outweighing  the  former  in  importance.  Motor  reflexes  may  be  noted  in 
the  quick  spurt  of  saliva  from  the  ducts  of  the  salivary  glands  upon 
infliction  of  pain  in  the  teeth,  and  by  the  spasmodic  contraction  of  the 
muscles  about  the  mouth  when  the  pulp  of  a  tooth  is  deliberately  irri- 
tated. Twitching  of  the  muscles  about  the  face  is  a  common  accom- 
paniment of  trigeminal  neuralgia. 

Before  direct  association  of  dental  diseases  with  pains  in  other  parts 
can  be  clearly  demonstrated  a  review  of  those  conditions  of  the  teeth 
attended  by  pain  must  be  made. 

500 


Fig.  382.— Plan  of  the  fifth  cranial  nerve,  showing  the  relationships  of  the  dental  nerves. 

(After  Flower.) 


502  REFLEX  DISORDERS  OF  DENTAL   ORIGIN. 

Dental  pain  arises  in  consequence  of  disorder  of  the  sensory  struct- 
ures ;  these  are  situated  in  the  pulp,  and  by  continuation  throughout 
the  dentin ;  and  in  the  pericementum.  The  roots  of  teeth  may  have 
unusual  anatomical  relations  with  other  sensory  structures  than  their 
own  pericementum.  Dental  pains,  therefore,  may  be  discussed,  first,  in 
connection  with  affections  of  the  dentin  and  pulp,  and,  secondly,  with 
those  of  the  pericementum. 

It  was  stated,  in  discussing  the  diseases  of  the  dental  pulp,  that  this 
organ  is  not  the  seat  of  the  tactile  sense,  and  that,  like  other  organs 
having  a  kindred  physiological  relationship,  irritation  excited  in  it  is 
not  located,  but  is  referred  to  some  other  part.  While  all  reflex  dental 
disturbances  are,  as  a  rule,  located  in  some  part  of  the  great  nerve- 
branch  supplying  the  source  of  irritation,  the  irritation  may  be  reflected 
to  distant  parts  :  first,  of  the  same  cranial  nerve,  and,  secondly,  to  other 
nerves.  That  is,  pain  having  its  origin  in  one  of  the  upper  teeth  is 
most  likely  to  be  referred  to  a  point  or  points  in  the  distribution  of  the 
superior  maxillary  nerve.  Disturbances  in  or  about  the  lower  teeth  are 
usually  referred  to  the  distribution  of  the  inferior  maxillary  nerve.  In 
affections  of  either  upper  or  lower  teeth  the  pain  may  be  referred  to  the 
first  division  of  the  fifth  nerve.  In  all  of  these  cases,  but  most  notably 
in  connection  with  disturbances  of  the  upper  teeth,  the  usual  symptom 
of  trifacial  neuralgia — tenderness  of  the  supra-  and  infra-orbital  nerves 
at  their  points  of  emergence  upon  the  face,  the  supra-  and  infra-orbital 
foramina — is  commonly  present. 

Cases  are  extremely  rare  where  the  reflex  pain  is  referred  to  the 
opposite  side ;  indeed,  so  unusual  is  this  occurrence  that  its  mention 
warrants  suspicion  that  other  sources  of  irritation  exist  upon  the  side 
referred  to. 

The  extent  or  acuteness  of  reflex  pain  bears  no  direct  relation  to  the 
apparent  extent  of  the  source  of  irritation. 

As  might  be  surmised  from  the  function  of  the  dental  pulp,  painful 
reflex  dental  disorders  are  more  common  in  connection  with  diseases  of 
the  pulp  than  with  those  of  the  pericementum. 

Reflex  Neuralgia  from  Exposed  Dentin. 

The  exposure  of  the  dentin  to  external  sources  of  irritation  is  fol- 
lowed by  reactions  governed,  first,  by  the  degree  of  sensitivity  inherent 
in  the  protoplasm  of  the  tissue ;  and,  secondly,  by  the  degree  of 
hypersensitivity  induced  in  it.  Reflex  disturbance  due  to  these  irri- 
tations is  more  common  in  the  class  of  women  called  "  neuralgics  "  than 
in  other  persons.  Like  direct  pulp-pains,  unless  actual  pressure  be 
exerted  upon  the  affected  tissue,  there  is  no  localized  pain.  In  the 
absence  of  deliberate  irritation,  the  pain  may  be  referred  to  any  portion 


REFLEX  NEURALGIAS  FROM  PULP-DISEASES.  503 

of  the  peripheral  distribution  of  the  fiftli  nerve  upon  the  face  ;  but  if 
an  acid  liquid,  such  as  lemon-juice  or  vinegar;  or  sugars,  be  taken  into 
the  mouth,  pain  is  excited,  which  is  referred  indefinitely  to  the  teeth  of 
one  side,  frequently  of  one  jaw.  Reflex  pains  due  to  this  cause  are 
much  more  likely  to  appear  when  there  is  but  little  loss  of  dentin. 

Wiien  carious  cavities  have  proceeded  to  any  depth  evidences  of 
direct  pulp-disturbance  are  obtained  through  the  increased  response  to 
thermal  changes. 

Reflex  pains  from  exposed  dentin  appear  most  common  in  connection 
with  exposures  at  the  neck  of  the  tooth  and  upon  abraded  areas. 
Obstinate  and  persistent  neural- 
gia, positively  referred  to  another 
nerve-branch,  may  apparently  owe 
its  origin  to  so  slight  a  cause  as  ex- 
posure at  the  neck  of  a  tooth  (Fig. 
383)  of  a  line  of  dentin.  The  proof 
of  the  connection  between  the  two 
is  made  clear  by  a  disappearance     ^^'"'  °^  <^'^"^  ".^p°'"/'  ^^^^^^""y  associated 

''  '^'^  with  reflex  pains. 

of  the  neuralgia  after  the  exposed 

dentin  has  been  subjected  to  the  action  of  powerful  caustics,  destroy- 
ing the  dentinal  filaments  to  some  depth.  The  connection  between  the 
two  may  be  revealed  only  by  accident ;  the  contact  of  a  tooth-pick,  a 
dental  instrument,  or  the  finger-nail  may  induce  a  paroxysm  of  pain. 

While  in  some  cases  the  dental  origin  of  reflex  pain  may  be  made 
clear  by  the  induction  of  a  painful  response  in  the  area  of  reflection, 
by  irritating  a  tooth-pulp,  this  reaction  is  not  constant.  The  causal 
relation  is  only  certain  when  the  cure  of  localized  dental  disease  is  fol- 
lowed by  a  disappearance  of  the  neuralgia  without  further  treatment. 
This  proof  should  be  exacted  in  all  cases. 

The  most  common  sources  of  neuralgic  attacks  about  the  face  are 
diseases  of  the  eyes  and  teeth.  In  general  terms,  diseases  of  the 
eye  give  rise  to  reflex  pains  referred  to  the  distribution  of  the  first 
branch  of  the  fifth  nerve  ;  diseases  of  the  teeth  usually  cause  reflex 
pains  in  either  the  superior  or  inferior  maxillary  divisions,  according  as 
the  upper  or  lower  teeth  are  affected.  In  all  painful  affections  of  these 
nerves  attention  should  at  once  be  directed  to  the  organs  named. 

Reflex  Neuralgias  from  Pulp-diseases. 

The  disturbances  require  classification  according  to  the  distance 
between  their  source  and  their  manifestations. 

In  the  Fifth  Pair  of  Nerves. — Pain  referred  to  a  different  spot 
or  area  than  its  origin  is  a  characteristic  of  all  pulp-diseases.  The 
extent  of  its  reflection  depends,  first,  upon  the  patient,  as  noted  in  con- 


504 


REFLEX  DISORDERS  OF  DENTAL   ORIGIN. 


Fig.  384. 


nectioD  with  the  reflex  pains  from  exposed  dentin  ;  and,  secondly,  upon 
the  variety  of  pulp-di.sease.  In  neuralgic  patients  any  variety  of  pulp- 
disease  may  cause  comparatively  distant  pains.  But,  as  Black  has 
pointed  out,^  the  general  rule  is,  that  the  more  chronic  and  profound 
degenerative  diseases  of  the  pulp  are  much  more  liable  to  give  rise  to 
distant  reflex  pains  than  are  acute  pulp-diseases. 

The  pains  of  acute  hypersemia  and  of  acute  inflammation  of  the 
pulp  are  usually  referred  to  the  region  of  the  tooth  affected,  or  to  a 
corresponding  nerve-trunk.  In  conditions  of  venous  hypersemia,  nodu- 
lar calcification,  chronic  inflammation,  and,  later  pulp-degenerations, 
the  pains  may  be  of  such  character  that  their  dental  origin  is  only 
determined  after  persistent  search.  Particularly  is  this  true  of  the 
growth  of  pulp-nodules.  The  source  of  the  reflex  pains  is  all  the  more 
obscure  from  the  fact  that  in  these  chronic  degenerations  direct  dental 
symptoms  may  be  entirely  absent,  and  are  only  elicited  upon  the  most 
searching  examination  and  exhaustive  tests. 

There  is  no  constancy  in  the  location  of  the  jmin  due  to  any  of 
these  causes ;  but  tenderness  of  the  eyeball  upon  pressure ;  persistent 
pain  in  the  temporal  and  anterior  auricular  regions,  particularly  in  con- 
nection with  pulp-diseases  of  the  lower  posterior  teeth  ;  in  the  ear  itself, 

a  common  site  of  the  reflex  pain  excited 
by  chronic  pulp-inflammation  and  sup- 
puration of  that  organ  ;  behind  the  ear, 
back  of  the  lower  border  of  the  mastoid 
processes,  tender  spots  may  develop  ;  ten- 
derness to  pressure  may  appear  at  the 
supra-  and  infra-orbital  or  mental  fora- 
men, and  about  the  chin.  In  the  same 
class  of  diseases  the  pains  may  frequently 
radiate  as  far  as  the  shoulder.  Many  of 
these  cases  receive  attention  from  the  gen- 
eral practitioner,  and  the  painful  attacks 
recurring  at  irregular  intervals  are  re- 
lieved by  analgesic  remedies — phenacetin,  acetanilid,  exalgin,  etc. — and 
no  attention  paid  to  a  probable  dental  source  of  the  disorder.  It  should 
be  a  routine  practice  to  examine  the  teeth  in  cases  presenting  pains  of 
the  type  and  in  the  situations  described.  Immediate  search  should  be 
made  for  teeth  containing  pulps  in  late  degenerative  stages  (see  Symp- 
toms of  Disease  of  the  Pulp).  Acute  diseases  of  the  pulp,  including 
suppuration  and,  notably,  abscess  of  the  pulp,  usually  have  attention 
directed  to  the  teeth  through  pain  induced  by  thermal  changes,  so  that 
their  diagnosis  is  quickly  made.     Not  so,  however,  with  the  chronic 

^  American  System  of  Dentistry,  vol.  i. 


Spots  of  tenderness  in  reflex  neural- 
gias of  dental  origin. 


REFLEX  PAINS  FROM  DISEASES  OF  THE  PERICEMENTUM.      505 

degenerative  changes,  except  possibly  of  pulp-nodult's ;  for  if  tlic  pulj) 
is  in  the  late  stages  of  degeneration,  it  may  require  repeated  a})plications 
of  cold  and  heat  to  elicit  a  response  from  teeth  which  do  not'  respond  by 
tenderness  upon  percussion. 

Failing  to  obtain  evidence  of  pulp-disorders,  examination  should 
be  made  for  ex})osed  and  hypersensitive  dentin.  Then,  examination 
of  the  pericemental  reaction  of  each  tooth  should  be  made  and  for  any 
evidences  about  the  teeth  pointing  to  pericemental  disturbance  (see 
later). 

Lauder  Brunton '  records  that,  in  his  own  case,  temporal  neuralgia 
accompanied  by  tender  eyeball  was  found  due  to  exposed  dentin  upon 
the  posterior  cervical  surface  of  a  lower  third  molar  (Fig.  383).  The  same 
writer  ^  announces  "  that  so  frequently  are  headaches  dependent  upon  de- 
cayed teeth  that  in  all  cases  of  headache  the  first  thing  I  do  is  to  care- 
fully examine  the  teeth  ;"  as  should  everyone  else.  Brunton  explains 
the  painful  reaction  upon  the  accepted  hypothesis  of  the  pathology  of 
megrim,  that  it  is  due  to  spasmodic  contraction  of  the  peripheral  end 
of  an  artery,  with  dilatation  of  the  proximal  portion.  "  Irritation  in 
the  tooth  is  reflected  to  the  cervical  sympathetic  ganglia  and  causes 
spasmodic  contraction  of  the  arteries  through  irregular  stimulation  of 
the  vasomotor  nerves." 

Reflex  Pains  from  Diseases  of  the  Pericementum. 

As  a  general  rule,  pericemental  pains  are  located  at  the  affected 
tooth ;  but  in  some  of  the  disorders,  particularly  those  in  which 
either  hypersemia  or  inflammation,  acute  or  chronic,  is  not  present,  the 
teeth  may  not  be  tender  upon  percussion,  and  yet  excite  reflex  pains 
in  other  parts,  the  proof  of  the  connection  being  determined  by  a  dis- 
appearance of  the  pain  upon  extraction  of  the  tooth.  The  roots  in 
such  cases  usually  present  either  a  hypertrophy  of  cementum,  or  show 
that  resorption  of  a  portion — it  may  be  a  major  portion — of  the  root 
has  occurred. 

In  cases  of  hypercementosis  it  is  assumed  that  the  source  of  the  irri- 
tation is  pressure  upon  the  nerves  of  the  pericementum  by  the  hyper- 
trophic growth.  Very  widespread  disorders  may  arise  from  this  source 
(see  cases  of  insanity,  etc.). 

Flagg  records''  many  varieties  of  trifacial  neuralgia;  pains  in  remote 
parts  of  the  body  ;  grave  functional  disorders  of  the  eye  and  ear  ;  and 
motor  disturbances — chorea,  epilepsy,  and  paralysis — having  a  direct 
demonstrable  connection  with  hypercementosis.     He  mentions  violent 

^  St.  Bartholomeid's  Hospital  Reports,  vol.  xix.     Reprinted  in  his  DmnJers  of  Digestion. 
'^  Ibid.  »  Dental  Cosmos,  1878. 


506  REFLEX  DISORDERS  OF  DENTAL   ORIGIN  OF  PERICEMENTUM. 

attacks  of  trifacial  neuralgia  as  the  most  common  reflex  disturbance 
from  this  source  ;  and  next,  long-continued  pains  in  the  ear  or  eye  of 
the  aifected  side.  The  existence  of  acute  disease  of  these  organs  is 
usually  diagnosed  by  the  general  practitioner.  He  states  that  oral 
and  ocular  disturbances,  both  functional  and  painful,  are  of  gradually 
increasing  severity. 

In  examining  for  a  dental  source  of  such  pains,  exposed  dentin,  pulp- 
diseases,  and  inflammatory  affections  of  the  pericementum  should  be  first 
excluded.  In  examinations  by  percussion  a  different  response  may  be 
obtained  from  some  one  tooth  than  from  the  others.  Hypercementosis 
of  a  particular  tooth  is  indicated  by  finding  the  gum-line  slightly  re- 
ceded, and  the  tooth-attachment  unusually  firm ;  if,  in  addition,  vague, 
heavy  dental  pains  have  persisted  at  intervals  over  a  long  period,  the 
diagnosis  is  probable.  It  is  only  certain  when  tapping  upon  the  tooth 
brings  on  a  paroxysm  of  neuralgia,  or  where  a  skiagraphic  view  actually 
exhibits  the  hypertrophic  growth.  The  remedy  is  extraction.  Any 
root-fragment  left  unextracted  may  perpetuate  the  reflex  disorder. 

Painful  affections  referred  to  the  neighboring  region  of  the  affected 
tooth,  or  diffused  through  the  distribution  of  the  corresponding  nerve- 
trunk,  or  to  the  eye  or  ear,  may  accompany  the  process  of  resorption 
of  the  roots  of  permanent  teeth.  Gillman  ^  records  a  case  where  facial 
paralysis  disappeared  upon  extraction  of  a  tooth  which  had  long  been 
the  seat  of  disturbances,  and  which  upon  extraction  revealed  resorption 
of  its  root. 

All  of  the  acute  or  chronic,  septic  or  non-septic  inflammations  of  the 
pericementum,  may  give  rise  to  reflex  pains.  In  many  of  these  cases 
the  cause  of  the  reflex  irritation  is  due,  perhaps,  to  sepsis,  rather  than 
to  a  pure  neurotic  connection.  The  most  common  causes  of  the  reflex 
pains  are  found  in  that  stage  of  pericemental  irritation  which  antedates 
acute  septic  apical  pericementitis,  and  which  accompanies  the  chronic 
inflammations  of  the  apical  pericementum  from  any  cause.  In  some 
of  these  cases  reflex  neuralgia  may  play  a  subordinate  part  to  general 
infection  from  the  focus  of  disease.  The  reflex  nervous  disorders  con- 
sist in  painful  disturbances  in  the  distribution  of  the  fifth  nerve  and  dis- 
orders of  special  senses,  particularly  that  of  hearing.  Unless  an  exacer- 
bation of  the  reflex  disorder,  or  symptoms  referable  to  that  region,  be 
induced  by  pressure  or  percussion  on  the  tooth,  a  causal  relationship  is 
only  made  out  by  either  relieving  an  existing  dental  disorder  or  extract- 
ing the  teeth.  The  symptoms  of  septic  intoxication  and  septicaemia  must 
be  carefully  differentiated  from  reflex  neuralgias  in  such  cases  :  the  latter 
are  rare ;  the  former  probably  more  frequent  than  supposed  in  connec- 
tion with  septic  dental  diseases. 

^  Boston  Med.  and  Surg.  Journal,  1867. 


PAIN  REFERRED  TO  NERVOUS  TRACTS  OTHER  THAN  FIFTH.     507 

Impacted  Teeth  as  a  Cause  of  Neuralgia. 

Neuralgia  of  varying  degrees  of  severity  is  a  common  accompaniment 
of  impacted  teeth.  It  is  most  frequently  noted  in  connection  with  erup- 
tion of  the  lower  third  molars,  not  only  because  this  tooth  is  the  one 
most  frequently  impacted,  but  because  of  the  anatomical  relations  of  its 
roots  with  the  inferior  dental  nerve. 

In  the  milder  forms  of  impaction,  those  in  which  eruption,  though 
delayed,  is  subsequently  completed,  the  pains  are  commonly  localized 
and  associated  with  but  occasional  attacks  of  rigidity  of  the  masseter 
muscles.  If,  however,  the  crown  present  horizontally  or  nearly  so,  and 
its  progress  is  arrested  by  impaction  against  the  posterior  wall  of  the 
lower  molar,  or  if  its  progress  be  arrested  by  permanent  imprisonment 
of  the  advancing  crown  between  the  posterior  surface  of  the  second 
molar  and  the  base  of  the  coronoid  process,  not  only  may  intense  local 
pains  be  induced,  but  severe  reflex  disturbances  of  both  a  sensory  and 
motor  character  may  occur.  In  some  of  these  cases  root-formation  is 
completed,  although  the  crown  of  the  tooth  does  not  advance,  in  which 
case  compression  of  the  inferior  dental  canal  and  its  contents  may  occur 
and  cause  grave  reflex  disturbances.  The  local  irritation  about  the  root, 
due  to  root-growth,  may  excite  continued  constructive  action  by  the 
pericementum,  and  the  hypertrophic  growth  in  its  turn  may  be  the 
source  of  reflex  neuralgias. 

Complete  imprisonment  of  the  entire  tooth  has  been  found  to  be  the 
exciting  cause  of  facial  neuralgias,  for  the  cure  of  which  extensive  sur- 
gical operations  have  been  performed. 

Impacted  cuspids  and  other  teeth  may  excite  no  other  symptoms  than 
reflex  neuralgia.  The  possible  connection  between  an  impacted  tooth 
and  neuralgia  is  made  out  after  excluding  other  dental  causes,  when  it 
may  be  observed  that  one  or  more  of  the  permanent  teeth  are  absent 
from  the  dental  arch,  at  dates  long  after  their  normal  time  of  eruption. 

A  condition  equivalent  to  partial  impaction,  in  which  dental  irrita- 
tion may  be  the  source  of  reflex  neuralgia,  is  seen  when  the  teeth  are 
crowded — jammed  into  arches  too  small  for  their  accommodation.  Dur- 
ing the  period  of  eruption  severe  maxillary  pains  may  recur  at  intervals. 

Pain  referred  to  Nervous  Tracts  other  than  the  Fifth. 

The  most  common  disturbance  appearing  in  other  cerebro-spinal 
nerves  than  the  fifth,  due  to  dental  diseases,  is  an  affection  of  the  eighth 
or  auditory  nerve.  Cases  of  deafness  have  been  recorded  due  to  dis- 
eases of  both  pulp  and  pericementum,  notably  to  hypercementosis. 
Deafness  which  has  persisted  for  a  long  period  has  been  markedly 
lessened  by  the  extraction  of  teeth  the  seat  of  disease.     Cases  of  sup- 


508  REFLEX  DISORDEES  OF  BEXTAL   ORIGIX. 

purative  otitis  media  have  been  regarded  as  having  pathological  associa- 
tion with  septic  diseases  about  the  teeth  from  the  fact  that  the  aural 
trouble  subsided  immediately  after  extraction  of  the  diseased  teeth. 

Sensory  disturbances  of  the  eye,  associated  with  dental  diseases,  have 
been  alluded  to  ;  in  addition  to  these,  grave  structural  and  functional 
diseases  of  the  eye,  traceable  to  dental  causes,  have  been  recorded,  such 
as  motor,  sensory,  and  special  sense-disturbances,  together  with  trophic 
disorders/  Among  the  latter  may  be  mentioned  corneal  inflammation 
and  ulceration  and  phlyctenular  conjunctivitis. 

Irregular  paralyses  of  the  third,  fourth,  and  sixth  nerves  of  the 
affected  side  have  been  noted. 

Amaurosis,  amblyopia,  and  functional  blindness  without  retinal  con- 
ditions to  account  for  it,  have  been  found  to  arise  from  notably  advanced 
degenerative  changes  in  the  dental  pulp,  sight  returning  to  the  eye  after 
loss  of  a  diseased  tooth.  De  Witt-  records  a  most  instructive  case 
where  temporary  blindness  was  associated  with  septic  apical  peri- 
cementitis, disappearing  after  evacuation  of  the  abscess,  and  reappear- 
ing when  secondary  inflammatory  action  arose  in  the  pericementum. 
The  ocular  affection  disappeared  permanently  and  almost  entirely  with 
the  loss  of  the  tooth.  The  history  of  this  case  illustrates  the  important 
causal  relationship  of  reflex  disturbances  with  late  pulp-degenerations ; 
for  the  blindness  arose  two  months  after  some  teeth  were  filled,  and 
existed  for  twelve  years  before  the  septic  apical  pericementitis  appeared. 

A  careful  examination  of  these  and  all  other  reflex  disturbances 
shows  that  pulp-degenerations  outnumber  all  other  affections  as  causes. 
Many  or  most  of  the  cases  are  recorded  by  general  practitioners,  who 
make  no  distinction  between  diseases  of  the  pulp  and  those  of  the  peri- 
cementum, but  a  reliable  diagnosis  of  the  conditions  is  made  possible 
by  the  accompanying  descriptions. 

Cases  of  ovarian  and  uterine  neuralgia  and  sciatica  and  cases  of 
obstinate  pains  in  the  toes  and  fingers  have  been  traced  to  dental  irrita- 
tion of  some  one  of  the  varieties  named ;  the  proof  of  association  being 
disappearance  of  the  pain  with  loss  of  the  tooth. 

Motor  Disturbances  from  Dental  Diseases. 

Motor  disturbances  due  to  dental  irritation  may  occur  as  recurrent 
or  persistent  contraction  or  paralysis  of  muscles,  together  with  more  or 
less  general  chorea ;  in  rare  instances  epilepsy  and  hystero-epilepsy. 
Twitching  of  muscles  of  the  affected  side  of  the  face,  ranging  from 
slight  affection  of  the  occipito-frontalis,  to  recurring  spasm  of  the  ele- 

'  See  Erubaker,  Araerican  System  of  Dentistry,  vol.  iii.,  for  very  full  and  detailed  dis- 
cussion of  these  subjects. 

''  Quoted  by  Brunton,  I)isorders  of  Digestion. 


DENTAL  PAIN  ARISING  FROM  OTHER  THAN  DENTAL  SOURCES.      509 

vators  and  depressors  of  the  lower  lip,  are  far  from  uiicoiumoii  phe- 
nomena attendant  npon  pulp-diseases. 

Contraction  of  the  masseter  muscle  is  a  common  accompaniment  of 
retarded  eruption  of  the  lower  third  molar,  which  may  be  intensified 
until  the  condition  is  fitly  termed  trismus,  in  some  cases  of  partial  im- 
paction of  the  teeth.  Partial  trismus  has  been  found  due  to  a  general 
overcrowding  of  the  dental  arch.'  Records  of  cases  of  torticollis,  due  to 
dental  diseases,  are  also  given  by  Brubaker. 

Cases  of  facial  paralysis,  and  cases  of  paralysis  of  one  arm,  of  para- 
plegia and  hemiplegia,  and  even  of  general  paralysis,  have  been  noted 
as  disappearing  after  the  extraction  of  diseased  teeth.  It  is  noteworthy 
that  in  these  cases,  as  well  as  in  several  cases  of  tetanus  recorded,  the 
possibility  of  an  infection  entered  into  the  pathogenesis  of  the  nervous 
diseases. 

Stellwagen^  records  a  case  where  symptoms  of  partial  hemiplegia 
followed  n])on  the  operation  of  capping  the  pulps  of  two  molar  teeth  ; 
the  symptoms  disappeared  promptly  upon  extraction  of  these  teeth. 

Cases  of  insanity  arising  from  dental  diseases  have  been  recorded ; 
they  were  both  maniacal  and  melancholic.  In  several  of  them  a  res- 
toration to  a  normal  mental  state  followed  promptly  upon  remt)val  of 
the  offending  teeth.  In  some  of  these  cases  a  pre-existing  maxillary 
neuralgia  directed  attention  to  the  teeth  as  possible  sources  of  the 
nervous  diseases. 

Dental  Pain  arising  prom  other  than  Dental  Sources. 

Conditions  of  pain  the  reverse  of  those  discussed — /.  e.,  pain  defi- 
nitely or  indefinitely  located  in  teeth  which  exhibit  no  morbid  condi- 
tions whatever — demand  occasional  attention  at  the  hands  of  the  dentist. 
These  painful  states  are  most  commonly  found  in  gouty  patients,  in 
whom  the  pain  may  have  the  character  of  pulp-pains,  or  of  perice- 
mentitis. The  pains  may  recur  at  intervals,  and  be  associated  with 
headache,  constipation,  etc.  The  gouty  origin  of  the  pains  is  indicated 
by  the  efficacy  of  sodium  salicylate  in  their  treatment,  without  any 
dental  treatment  whatever. 

Chronic  malarial  poisoning,  as  stated  in  the  beginning  of  this 
chapter,  may  give  rise  to  periodical  attacks  of  maxillary  neuralgia. 
As  in  the  gouty  cases,  the  constitutional  cause  of  the  disturbance  is 
made  clear  through  the  therapeusis  most  effective,  viz.,  the  periodical 
recurrence  of  the  pain  leads  to  the  inference  of  a  malarial  origin,  and 
to  the  administration  of  quinin. 

Syphilitic  pains  in  the  jaws  have  a  pericemental  character,  and  other 
evidences  of  syphilis  are  present  which  point  to  a  diagnosis. 

'  Brubaker.  ^  Private  communication. 


510  REFLEX  DISORDERS  OF  DENTAL   ORIGIN. 

Pains  in  or  about  the  teeth  are  occasional  accompaniments  of  dis- 
eases of  the  brain  or  its  vessels,  and  of  diseases  of  the  uterus,  kidneys, 
and  bladder. 

Disease  in  any  portion  of  the  fifth  cranial  nerve  may  be  referred  to 
the  teeth. 

Dental  pain  during  pregnancy,  without  any  direct  evidence  of  dental 
disease,  is  relatively  common. 

Disorders  of  the  lower  bowels,  causing  constipation,  may  give  rise 
to  pain  referred  to  one  or  more  teeth,  the  pain  ceasing  promptly  upon 
the  administration  of  au  active  evacuant. 


CHAPTER   XXIX. 

INFECTIONS  OF  AND   FROM  THE   MOUTH,  AND  STERILIZA- 
TION. 

The  conditions  found  in  the  human  mouth,  as  pointed  out  in  Chap- 
ters III.  and  YI.,  are  of  a  character  which  afford  lodgement  to,  and 
opportunities  for  multiplication  of,  many  forms  of  hacteria,  both  sapro- 
phytic and  parasitic.  The  oral  conditions  are,  however,  not  entirely 
constant,  so  that  at  different  periods  they  may  favor  the  develop- 
ment of  some  special  bacterial  forms  more  than  others.  The  nature 
of  these  variations  has  not  been  made  out,  although  their  effects  are 
indubitable.  Again,  the  oral  bacterial  inhabitants  are  not  constant 
as  to  species,  for  while  there  are  many  forms  which  appear  to  be 
invariable  occupants  of  the  oral  cavity,  many  pathogenic  forms  are  but 
accidental  residents.  Becoming  resident,  they  may  or  may  not  develop 
according  as  they  find  in  the  mouth  a  suitable  soil.  The  nature  of 
what  constitutes  a  suitable  or  unsuitable  soil  has  not  been  determined, 
although  in  some  cases  extra-oral  culture-experiments  furnish  some 
indications. 

Bacterial  growth,  as  causes  of  dental  caries  and  diseases  of  the 
pulp  and  pericementum,  have  been  discussed  in  connection  with  those 
several  diseases.  It  was  shown  that  the  pyogenic  cocci  are  almost 
constant  inhabitants  of  the  human  mouth.  There  appeared  also  evi- 
dence that  some  of  the  reflex  disorders  of  distant  parts  are  directly 
traceable  to  septic  processes  about  the  teeth,  and,  in  addition  to  these, 
suppurative  diseases  in  other  parts  become  curable  after  removal  of  a 
septic  tooth  ;  such  conditions  representing  infection  from  a  local  dental 
infection,  an  important  aspect  of  dental  pathologv. 

The  infections  arising  from  the  growth  of  mouth-fungi  are  local  and 
general.  The  phrase  fungi  is  used  in  this  connection,  because  other 
classes  beside  the  fission-fungi  (schizomycetes)  are  pathogenic  also.  Both 
the  thread-fungi  (hyphomycetes)  and  bud-fungi  (blastomycetes)  induce 
morbid  conditions  in  the  human  mouth. 

The  notable  fungus  of  the  blastomycetes,  is  the  saccharomvces  albi- 
cans ;  this  organism,  when  classified  by  mycologists  as  a  thread-fungus, 
was  known  as  the  oidium  albicans  (Fig.  3<S5).  The  growth  of  this 
organism  illustrates  forcibly  the  influence  of  soil  on  the  growth  of  fungi. 
It  does  not  occur  in  the  mouths  of  healthy,  well-nourished,  and  clean 
children  with  good  surroundings.     It  is  a  disease  of  childhood,  particu- 

511 


512 


INFECTIONS  OF  AND  FROM  THE  MOUTH. 


larly  of  nurslings,  and  its  occurrence  is  almost  always  confined  to  bottle- 
fed  babies  whose  feeding-bottles  are  kept  in  an  unclean  condition.     De- 


FiG.  385. 


Saccharomyces  albicans,  thrush  fungus.    (Miller.) 


bility  of  the  oral  tissues  is  established  in  consequence  of  the  fermen- 
tations arising  from  the  source  named,  furnishing  a  favorable  condition 
for  the  development  of  the  saccharomyces  (oi'dium)  albicans.  The  con- 
dition produced  is  known  as  thrush.  The 
infection  may  be  carried  from  one  child  to 
another,  and  if  the  fungus  be  brought  in 
contact  with  an  abraded  mucous  surface  of 
an  adult  it  may  develop. 

The  fungus  burrows  between  the  epi- 
thelial cells  of  the  mucous  membrane 
(Fig.  386),  not  beyond  it.  It  first  ap- 
pears in  small  spots,  which  coalesce,  until 
large  patches  of  a  membranous-like  growth 
cover  extensive  surfaces,  spreading  by  con- 
tinuity to  all  of  the  mucous  surfaces  asso- 
ciated with  the  mouth. 

As  bud-fungi  flourish  only  in  media  of 
acid  reaction,  the  use  of  alkaline  washes  is 
indicated  in  the  treatment  of  this  condition. 
Wiping  the  patches  with  dilute  phenol 
sodique  is  also  eflicacious. 

The  hyphomycetes,  or  thread-fungi,  al- 
though associated  with  diseases  of  the 
human  skin,  have  not  had  any  pathologi- 
cal significance  attached  to  them  as  regards 


Pavement-epithelium  covered  with 
spores  of  the  oidium  albicans.  (Ch. 
Robin.) 


the  mouth. 


Miller,  Micro-organisms  of  the  Human  Mouth. 


STOMATITIS.  513 

Infective  Bacteria  of  the  Mouth. 

Bacteria,  hein(>;  ever  present,  iiuist  alwavs  play  a  part  in  either  origi- 
nating, modifying,  or  associating  with  all  oral  diseases. 

That  the  progressive  decomposition  of  albuminons  substances,  always 
present  in  the  mouth  to  a  greater  or  less  degree,  by  the  action  of  sa- 
prophytic fungi,  must  give  rise  to  derivatives  of  all)umin,  many  of  them 
toxic  in  effects,  would  be  surmised  even  in  the  absence  of  experimental 
demonstration,  a  suspicion  confirmed  by  experiment.  Vulpian^  pro- 
duced septicaemia  by  vaccinating  animals  with  the  saliva  of  a  healthy 
man.  Griffin^  showed  that  the  parotid  saliva  (pure)  is  harmless.  The 
saliva,  if  boiled,  exerts  no  toxic  action,  from  which  it  is  clear  that  it 
derives  its  toxic  substances  from  the  mouth.  The  saliva  of  individuals 
differs  at  times  in  the  degree  of  its  poisonous  action.  In  some  diseases 
it  becomes  intensely  toxic. 

Of  the  many  oral  bacterial  forms,  some  are  cultivable  and  some 
are  not;  hence  the  specific  effects  of  some  are  discovered,  others  are 
doubtful. 

With  regard  to  local  affections,  other  than  those  described  in  the 
body  of  this  book,  a  bacterial  causation  has  been  made  out  in  some, 
but  in  others  it  has  not. 

Stomatitis. 

Definition. — By  stomatitis  is  meant  a  catarrhal  inflammation  of  the 
mucous  membrane  of  the  mouth. 

Varieties. — It  may  be  localized,  as  in  marginal  gingivitis,  or  be 
diffuse ;  and,  again,  be  accompanied  by  localized  ti.ssue-destructions — 
ulcerations  ;  the  character  of  the  ulceration  differs  according  to  its  prob- 
able causes. 

Occurrence. — Most  of  these  diseases  belong  to  the  period  of 
childhood,  although  localized  ulcerative  stomatitis  may  appear  in  the 
adult. 

Causes. — The  causes  of  stomatitis  are  so  many  and  varied  as  to 
suggest  a  classification  under  heads  according  to  assignable  causes. 
While  it  is  true  that  bacterial  infection  has  not  been  shown  to  be 
a  direct  cause  of  all  of  these  conditions,  some  degree  of  causal  rela- 
tionship is  probable  in  all  of  them.  The  disease  may,  however,  be 
included  under  two  heads  according  as  they  are  or  are  not  localized,  and 
necrotic.  The  less  localized  cases  appear  as  a  diffuse  catarrhal  affec- 
tion, affecting  wide  areas  of  the  oral  mucous  membrane ;  the  others 
appear  as  spots  of  localized  tissue-destruction  attended  by  surrounding 
hypersemia. 

1  Quoted  by  Miller.  -^  Ibid. 

33 


514 


INFECTIONS  OF  AND  FROM  THE  MOUTH. 


Catarrhal 
Stomatitis 


Local 


Symptomatic 


r  Simple. 

{ 
L  Infectious    .  .  . 

^  Eruptive  fevers. 
Syphilis. 
Tuberculosis. 
Typhoid  fever. 

Drug-action  .  . 


r  Fermentations. 
A   Diphtheria. 
'^  Gonorrhoea. 


Local 


lodids. 
Mercury. 
Lead. 
Pilocarpin. 


Symptomatic 


Aphthae. 

Thrush. 

Noma. 

Herpes. 
Ulcerative  Syphilis 

Stomatitis  ..A  ^      (primary). 

r  Syphilis /  Secondary. 

I      -^^  L  Tertiary. 

"]   Tuberculosis 
[^      (local). 

SIMPLE    LOCAL    CATARRHAL    STOMATITIS. 

The  general  symptoms  of  catarrhal  inflammation — heat  and  swelling, 
with  deepened  color  of  the  mucous  membrane,  followed  by  increased 
secretion  and  exudation — attend  several  types  of  oral  irritation,  such 
as  the  irritation  induced  by  erupting  teeth,  particularly  of  the  deciduous 
teeth.  Inflammation  of  any  degree  may  follow  the  taking  into  the 
mouth  of  caustic  chemical  substances,  such  as  caustic  alkalies,  mineral 
acids,  carbolic  acid,  etc.,  which  are  occasionally  taken  by  children. 
Other  irritant  drugs,  and  very  hot  fluids  may  produce  similar  results. 
General  catarrhal  stomatitis  is  a  frequent  affection  of  confirmed  smokers, 
and  of  drinkers  of  distilled  liquors. 

The  cure  of  these  conditions  consists  in  the  removal  or  neutralization 
of  the  cause,  and  the  use  of  local  sedatives  and  antiseptics  to  allay  irri- 
tation and  prevent  infection.  The  most  effective  method  of  treating 
the  inflammatory  condition  is  by  antiseptic  sprays,  such  as  diluted 
Dobell's  solution,  followed  by  sprays  of  strong  solutions  of  potassium 
chlorate.  If  much  pain  exist,  phenol  sodique  is  an  admirable  sedative 
antiseptic,  used  in  10-20  per  cent,  solution,  as  a  spray. 

INFECTIVE    LOCAL    CATARRHAL    STOMATITIS. 

This  in  some  degree  is  a  common,  perhaps  the  necessary,  antecedent 
condition  to  many  of  the  ulcerative  forms  of  stomatitis.     It  is  probable 


STOMATITIS.  515 

that  many  of  the  cases  of  stomatitis  found  in  infants,  children,  and 
adults  are  due  to  unusual  fermentations  occurring  in  the  mouth.  Chil- 
dren whose  nursing-bottles  are  not  kept  clean  ;  those  who  at  a  later  age 
suffer  from  neglect  of  the  teeth  and  from  the  effects  of  improper  food  ; 
adults  in  whose  mouths  dental  diseases  are  widespread,  and  whose  oral 
hygiene  is  very  faulty  :  all  exhibit  abnormal  conditions  of  the  oral 
mucous  membrane — more  or  less  swelling,  softness,  and  deepened  color 
of  the  mucous  membrane,  a  coated  tongue,  and  offensive  breath,  with 
an  increase  of  oral  secretions. 

The  complexus  of  oral  symptoms  is  commonly,  and  also  by  the 
general  practitioner,  regarded  as  symptomatic  of  gastric,  intestinal,  and 
hepatic  disorders,  as  doubtless  they  are,  but  the  causal  relationship  is 
in  many  cases  probably  the  reverse  of  that  implied  in  such  opinions,  for 
it  is  probable  (see  later)  that  the  disturbances  of  digestion  are  fermenta- 
tive in  character,  and  the  organisms  causing  them  find  their  way  to  the 
stomach  from  the  mouth,  which  was  first  affected.  The  treatment  of 
this  condition  consists  in  the  correction  of  its  causes,  their  non-repetition, 
and  the  continued  use  of  oral  antiseptics. 

While  the  point  of  first  attack  of  the  diphtheria  bacillus  is  most  marked 
about  the  soft  palate  and  tonsils,  the  false  membrane  forming  there  and 
spreading  to  the  pharynx,  more  or  less  general  inflammation  of  the 
oral  mucous  membrane  also  occurs.  The  gonococcus  may  be  lodged  in 
some  portion  of  the  oral  cavity  and  excite  its  specific  effects  upon  con- 
tiguous mucous  membranes. 

SYMPTOMATIC    CATARRHAL    STOMATITIS. 

Stomatitis  in  its  catarrhal  form  is  usually  associated  with  the  early 
and  later  stages  of  the  eruptive  fevers,  scarlet  fever,  smallpox,  etc.  In 
scarlet  fever  and  smallpox  evidences  of  direct  infection  of  the  moutli 
exist  and  the  inflammatory  reaction  is  pronounced. 

Catarrhal  stomatitis  is  one  of  the  manifestations  of  secondary  and 
tertiary  syphilis,  antedating  the  appearance  of  tissue-necrosis  (ulcera- 
tions). 

More  or  less  catarrhal  stomatitis,  confined,  it  may  be,  to  the  mucous 
membrane  of  the  gums,  is  common  in  the  mouths  of  phthisical  patients  ; 
this  condition  exhibits  no  evidence  of  direct  association  of  the  local 
development  of  the  bacillus  of  tuberculosis,  because  no  tubercular 
ulcers  may  arise  or  threaten. 

The  stomatitis  of  typhoid  fever  may  be  regarded  as  an  almost  essen- 
tial feature  of  the  disease. 

The  effects  of  drug-elimination  by  the  oral  tissues  have  been  already 
discussed  (see  Chapter  XXIV.). 


516  INFECTIONS  OF  AND  FROM  THE  MOUTH. 

ULCERATIVE    STOMATITIS. 

It  has  been  customary  to  describe  ulcerative  stomatitis  as  simple  and 
infective ;  in  all  probability  these  ulcerations  are  always  infective. 
Like  catarrhal  stomatitis  the  ulcerative  disease  may  have  only  a  local 
significance  or  be  indicative  of  some  general  disease. 

Ulcerative  Stomatitis  of  Local  Significance. — The  more  usual  or 
infantile  forms  of  these  disorders  are  a  sequel  of  catarrhal  stomatitis, 
at  least  of  an  acquired  debility  of  the  oral  tissues,  and  their  primary 
cause  is,  therefore,  the  cause  producing  a  condition  of  mucous  mem- 
brane which  permits  the  growth  of  infective  organisms.  One  of  these 
diseases,  thrush,  has  already  been  described.  The  others,  aphthae,  herpes 
labialis,  and  noma,  are  all  probably  due  to  the  action  of  organisms. 

Aphthae. — This  affection  is  common  in  its  isolated  form,  as  the  canker 
sore.  In  the  catarrhal  stomatitis  of  children,  during  or  after  dentition, 
multiple  sores  frequently  make  their  appearance.  The  condition  can 
best  be  studied  when  it  appears  as  an  isolated  sore  in  the  mouth  of  the 
adult.  The  most  common  situation  of  the  sore  is  at  the  junction  of 
two  mucous  surfaces,  such  as  that  of  the  gum  with  the  lip  or  cheek,  or 
that  of  the  floor  of  the  mouth  with  the  gum  or  tongue.  Redness  dif- 
fused over  a  limited  area,  followed  by  a  nodular  hardening,  occurs, 
during  which  local  pain  is  annoying ;  the  centre  of  the  hardened  area 
breaks,  forming  a  raw  surface,  which  quickly  acquires  a  rough  white 
coating  which  is  easily  removable.     The  sores  are  very  painful. 

This  condition  follows  so  constantly  upon  the  taking  of  very  indi- 
gestible food,  such  as  lobster,  Welsh  rarebits,  etc.,  that  acute  indigestion 
must  be  regarded  as  having  some  causal  relationship  with  it.  It  is  also 
of  frequent  occurrence  in  the  mouths  of  dyspeptics ;  that  form  of 
gastric  disturbance  attended  by  a  deficiency  of  hydrochloric  acid  in  the 
gastric  juice  appears  to  have  a  constant  association  with  it. 

The  appearance  of  ulcerative  stomatitis  in  children,  together  with 
its  treatment,  was  discussed  in  the  chapter  on  Dentition. 

The  general  treatment  of  these  ulcerations  appearing  in  the  mouths 
of  children  is  the  administration  of  a  laxative,  and  the  subsequent 
administration  of  listerine,  gtt.  x,  every  two  hours.  Locally  the 
mucous  membrane  is  to  be  sprayed  with  pyrozone,  followed  by  sprays  of 
strong  solutions  of  potassium  chlorate. 

Localized  aphthous  patches  in  the  adult  are  promptly  relieved  by  the 
administration  of  calomel,  gr.  ij  at  night,  followed  in  the  morning  by  a 
mild  saline.  The  local  sore  is  dried  and  touched  with  pure  carbolic 
acid.  The  administration  of  alkalies  before  meals,  and  hydrochloric 
acid  after  meals,  usually  remedies  the  gastric  condition,  unless  it  be  of 
long  standing. 


STOMATITIS. 


517 


A  variety  of  aphthous  sore  is  called,  from  the  anatomical  situation 
of  the  ulcers,  follicular  stomatitis.  Irritation  and  swelling  of  the 
mucous  follicles  in  the  palatal,  buccal,  and  labial  mucous  membrane  are 
accompanied  by  more  or  less  localized  inflammation ;  the  follicles 
become  ulcerous,  the  small  ulcers  having  a  uniform  size.  This  condi- 
tion quickly  disappears  under  the  treatment  advised  for  ulcerative 
stomatitis.  An  indication  of  the  bacterial  origin  of  all  of  these  dis- 
turbances is  seen  in  the  efficacy  of  antiseptics  used  in  their  treatment. 

Noma,  Cancrum  Oris,  Gangrene  of  the  Mouth. — In  ill-fed, 
ill-nourished,  and  ill-kept,  cachectic  children,  the  debilitation  of  the  oral 
tissues  may  exceed  the  grades  given,  and  a  disease  probably  bacterial  in 
origin  may  arise  whicli  leads  to  widespread  necrosis  of  the  cheeks  and 
maxillae.  The  condition  is  called  gangrene  of  the  mouth,  noma,  or  can- 
crum  oris  ;  the  latter  term  has  been  applied  to  the  less  severe  varieties. 

This  disease  may  make  its  appearance  as  an  ulcer  at  the  junction  of 
cheek  and  gum  ;  in  other  cases  a  severe  stomatitis  arises  without  a 
primary  ulcer.  A  greater  or  less  extent  of  the  cheek  acquires  a  board- 
like hardness,  becoming  livid  ;  the  overlying  mucous  membrane  breaks. 


Fig.  387. 


Noma.    (J.  Lewis  Smith.) 


exhibiting  a  large  slough.  The  necro.sis  extends  toward  cheek  and  jaw, 
destroying  further  tissue.  The  sloughs  undergo  putrefactive  decom- 
position, emitting  a  stench.  The  destruction  of  tissue  may  be  arrested, 
or  may  proceed,  destroying  in  a  few  days  the  entire  ciieek  and  bony 


518  INFECTIONS  OF  AND  FROM  THE  MOUTH. 

tissues.  In  the  more  severe  cases  the  disease  is  almost  invariably  fatal, 
because  the  extent  of  the  tissue-destruction  bears  a  constant  relation  to 
the  underlying  debility  of  the  patient.  It  will  be  seen  that  the  disease 
resembles  malignant  pustule  or  carbuncle  in  several  of  its  features. 

While  no  specific  organism  has  been  isolated  as  pathogenic  of  this 
condition,  Schimmelbosch  ^  found  a  bacillus  (pure  culture)  upon  the 
borders  of  the  necrosis,  which  may  prove  pathogenic  of  noma. 

These  cases  are  purely  medical,  so  that  their  full  discussion  is  not 
warranted  in  these  pages.  The  principle  of  treatment  is  to  improve 
the  general  condition  of  the  child,  destroy  the  probable  infection  in  the 
borders  of  the  still  vital  tissue,  and  promote  sloughing  of  the  necrosed 
tissue. 

Syphilitic  Affections  of  the  Mouth. — The  recognition  of  syphilitic 
lesions  about  the  mouth  is  of  vital  importance  to  the  dental  operator, 
first,  because  by  the  recognition  he  may  take  steps  to  prevent  the  car- 
riage of  infection  to  innocent  patients  ;  and,  secondly,  that  he  may  avoid 
inoculation  of  himself  by  the  poison. 

In  the  minds  of  many,  syphilis  is  associated  with  the  lower  class  of 
persons,  who  are  confirmed  cUbaucMs.  While  it  is  undoubtedly  true  that 
its  prevalence  is  most  marked  in  this  class  of  persons,  it  appears,  and 
with  horrible  frequence,  in  persons  who  would  be  little  suspected  of 
having  such  infection.  The  operator  is  to  be  guided  in  his  ojainions 
and  precautions  in  this  matter,  not  by  the  social  status  of  the  patient, 
but  by  the  nature  of  the  morbid  conditions  existing. 

Syphilis  is  usually  divided  into  three  stages,  primary,  secondary,  and 
tertiary ;  to  these  may  be  added  a  fourth  stage,  viz.,  in  patients  who 
have  been  discharged  as  cured  mild  manifestations  of  disorders,  par- 
ticularly of  the  skin  and  mucous  membranes,  make  their  apjDearance 
from  time  to  time,  and  disappear  promptly  upon  the  administration  of 
iodids. 

The  first  stage  of  syphilis — primary  syphilis — consists  in  the  forma- 
tion of  the  primary  sore  or  chancre,  and  the  involvement  of  the  nearest 
lymphatic  glands.  Secondary  syphilis  is  attended  by  fever,  eruptive 
inflammations  of  the  skin,  inflammation  and  superficial  ulcerations  of 
mucous  structures.  In  tertiary  syphilis  destructive  inflammation  of 
the  skin,  mucous  membranes,  and  connective  tissues  occurs,  together 
with  the  formation  of  specific  tumors — gummata. 

Some  difference  of  opinion  exists  among  syphilographers  as  to  the 
relative  infective  power  of  the  secretions  from  the  several  lesions  of 
syphilis.  All  are  agreed,  however,  that  the  secretions  from  the  second- 
ary lesions  observed  in  and  about  the  mouth  are  highly  infective.  It  is 
the  part  of  prudence  to  regard  all  syphilitic  lesions  as  infective.  All 
^  Miller,  Dental  Cosmos,  Sept.,  1891. 


SYPHILITIC  AFFECTIONS  OF  THE  MOUTH.  519 

these  stao;es  of  syphilis  may  be  seen  in  the  human  mouth.  It  is  to  be 
remembered  that  if  the  mucous  membrane  of  the  mouth  be  infected 
from  a  mucous  patch  (a  secondary  lesion),  the  acquired  disease  will 
ap])ear,  not  as  a  mucous  patch,  but  as  a  chancre.  It  is  from  mucous 
patches  that  infection  is  most  to  be  feared. 

Primary  Syphilis  of  the  Mouth. — Causes. — The  primary  lesion 
of  svphilis,  chancre,  when  found  in  the  mouth  is  a  consequence  of  direct 
infection  from  a  syphilitic.  The  infection  occurs  from  contact  of  the 
mucous  surface  of  the  mouth  with  a  syphilitic  lesion  upon  another  per- 
son :  it  has  been  transmitted  by  kissing  :  it  may  occur  from  using  a 
glass  or  cup  previously  used  by  a  syphilitic,  by  smoking  cigars  or 
cigarettes  which  have  been  made  by  syphilitic  cigarmakers,  who  have 
applied  the  tongue  to  the  tobacco  in  attaching  the  wrapper.  Any  of 
the  articles  named,  or  the  contact  of  any  article  which  has  been  in 
contact  with  a  syphilitic  lesion,  if  brought  in  contact  with  an  abraded 
mucous  surface  may  cause  infection. 

The  infection  may  be  transferred  from  patient  to  operator  if  the 
fingers  have  any  abraded  surface,  or  if  the  surface  is  broken  accidentally 
by  an  instrument.  Infection  may  be  transmitted  from  one  patient  to 
another  by  any  instrument,  appliance,  or  article  used  by  the  syphilitic 
being  afterward  used  by  an  innocent  person.  Drinking-glasses,  mouth- 
mirrors,  exploring-instruments,  rubber-dam,  rubber-dam  clamps,  saliva 
ejector  tubes,  lancets,  forceps,  or  any  other  instruments  may  be  the 
medium  of  communication.  Diu'ing  and  since  the  time  of  Hunter  the 
use  of  teeth  from  syphilitic  patients  in  plantation  operations  has  been 
a  clearly  recognized  medium  of  communication. 

Appearances  and  Diagnosis — "  The  primary  lesion  of  syphilis  never 
makes  its  appearance  before  ten  days  after  infection  ;  the  maximum 
period  is  about  ninety  days  ;  the  average  is  twenty-one  days."  ' 

It  usually  appears  as  a  single,  elevated,  hard  papule.  In  cases  of  dental 
infection,  most  frequently  about  the  lips,  the  papule  loses  its  epithelial 
coating  after  some  days.  The  induration  surrounding  the  papular  mass 
increases  until  the  papule,  which  is  now  raw  and  in  a  process  of  ulcera- 
tion, appears  surrounded  by  a  ring  of  cartilaginous  hardness.  This  indu- 
ration is  the  one  distinguishing  feature  of  the  chancre,  which  is  not 
painful.  In  about  a  week  after  the  appearance  of  the  primary  sore, 
swelling  of  the  submaxillary  lymphatic  glands  is  observed.  In  case  the 
chancre  appear  upon  the  tongue,  the  subhyoid  lymphatic  glands  are 
swollen.^  Unless  pyogenic  infection  have  occurred,  the  lymphatic 
involvement  is  not  inflammatory,  there  being  no  pain  present.  In  from 
three  to  four  weeks  the  sore  disappears,  leaving  no  signs  of  its  site  in 
some  cases ;  in  others,  some  induration  may  persist. 

'  Gross,  System  of  Surgery.  *  Park,  Surgery. 


520  INFECTIONS  OF  AND  FROM  THE  MOUTH. 

The  diagnosis  of  this  condition  is  the  important  consideration,  so  far 
as  the  dental  practitioner  is  concerned,  its  treatment  being  the  province 
of  the  general  surgeon. 

The  elevation  of  the  sore,  its  induration,  and,  if  obtainable,  the  time 
of  inoculation,  are  diagnostic  data.  The  sore  is  single,  and  there  is 
hard,  nodular,  painless  swelling  of  the  neighboring  lymphatics.  A  single 
ulcer  of  ulcerative  stomatitis  may  in  some  degree  simulate  the  appear- 

FiG.  388. 


Chancre  of  the  lip. 

ance  of  a  very  small  chancre.  It  may  exhibit  dight  induration,  but  its 
irregular  form,  situation,  painfulness,  and  the  usual  absence  of  lymphatic 
involvement,  together  with  its  prompt  disappearance  after  sterilizing 
the  mouth  and  cauterizing  the  ulcer,  will  differentiate  the  two  sores. 
If  the  chancre  be  upon  the  tip  or  sides  of  the  tongue,  where  it  is  sub- 
jected to  irritation,  it  may  become  very  large  and  bear  a  close  resem- 
blance to  epithelioma  of  that  organ. 

It  is  a  wise  precaution  to  view  all  sores  about  the  mouth  as  possibly 
infectious.  All  errors  of  diagnosis  in  this  direction  will  be  more  than 
compensated  for  by  the  assurance  of  non-transference  of  infection. 

Secondary  Syphilis  of  the  Mouth. — The  secondary  manifes- 
tations of  syphilis  are  observed  in  and  about  the  mouth,  no  matter 
what  the  location  of  the  primary  lesion  may  have  been ;  they  are  the 
result  of  a  general,  not  a  local,  infection. 

Secondary  affections  of  the  mucous  tissues  appear  in  from  four  to 
twelve  weeks  after  the  appearance  of  the  primary  lesion.  Sore  throat, 
due  to  inflammation  of  the  mucous  membrane  of  the  pharynx  and  parts 
about,  is  almost  constant ;  together  with  syphilitic  hoarseness,  due  to 
the  extension  of  the  affection  to  the  mucous  membrane  of  the  larynx. 

The  appearance  of  copper-colored  areas  upon  some  portion  of  the 
mucous  membrane,  on  the  tonsil,  pharynx,  soft  palate,  lips,  or  bucco- 
labial  surface,  precedes  the  loss  of  ej^ithelium  over  these  surfaces,  which 
soon  occurs,  forming  the  most  virulently  contagious  lesion  of  syphilis,  the 
mucous  patch.     The  patches  become  covered  with  a  grayish-white  pasty 


SYPHILITIC  AFFECTIONS  OF  THE  MOUTH.  521 

covering,  resembling;  the  ulcerations  of  non-specific  stomatitis.  So 
close  is  the  resemblance  that  a  differentiation  can  only  Vje  made  at  times 
by  additional  evidences  of  secondary  syphilis.  Sinjj:le  patches  may 
coalesce,  forming  large  irregular  areas  (covered  by  a  grayish-wliite  pel- 
licle. These  patches  are  rarely  painful.  Ulcerations  having  ragged, 
irregular  outlines  may  appear  at  the  sites  of  the  original  patches  or  in 
other  situations,  and  exhibit  a  tendency  to  spread. 

The  diagnosis  of  the  condition  is  determined  by  a  discovery  of  other 
lesions  of  secondary  syphilis  ;  skin-eruptions,  falling  out  of  the  hair 
(alopecia),  and  the  areas  of  copper-colored  eruption  upon  the  mucous 
membrane  of  the  pharynx  and  soft  palate. 

Hugenschmidt  ^  has  observed  among  syphilitics,  who  presented  no 
local  lesions,  the  frequent  nocturnal  occurrence  of  indefinitely  located 
dental  pains,  spreading  to   the  palatal  region. 

Tertiary  Syphilis  of  the  Mouth. — The  syphilides  of  the 
secondary  stage  arise  in,  and  are  confined  to,  the  mucous  and  dermal 
structures  ;  those  of  the  tertiary  stage  arise  in  the  deep  connective  tis- 
sues, and  are  frequently  associated  with  periosteum. 

Tertiary  lesions,  as  seen  by  the  dentist,  are  usually  in  the  form  of 
ulcers  of,  first,  the  soft  or  hard  palate,  and  of  the  tongue  or  lips.  In 
the  earlier  stages  hard  nodular  formations  may  be  noted  as  antecedents 
to  the  ulcerations.  Chronic  periostitis  of  the  palatal  processes  may 
occur,  leading  to  the  formation  of  localized  thickenings.  In  other  cases, 
in  the  soft  palate,  upon  the  tongue,  or  in  the  hard  palate,  localized  swell- 
ings may  occur ;  the  overlying  mucous  membrane  breaks,  establishing 
an  ulcer,  which  may  perforate  the  soft  palate,  and  destroy  a  portion  of 
the  palatal  process,  or  form  large  ulcers  on  the  tongue.  These  lesions 
appear  in  from  two  to  five  years  after  the  secondary  manifestations. 

Although  there  is  much  doubt  as  to  the  degree  of  infectiveness  of 
these  tertiary  lesions,  precautions  as  to  sterilization  should  be  taken  as 
with  the  primary  and  secondary  lesions.  A  defined,  ragged  ulcer  occu- 
pying the  hard  or  soft  palate,  which  has  persisted  for  a  long  time, 
should  always  be  viewed  with  suspicion,  and  a  search  be  made  for  other 
evidences  of  syphilis. 

These  ulcerations  appearing  upon  the  side  of  the  tongue  may  closely 
simulate  epithelioma  of  that  organ.  The  confusion  is  increased  if,  in 
consequence  of  the  presence  of  jagged  teeth,  a  continuous  irritation  is 
excited.  Moreover,  leukoplakia  of  the  cheeks,  a  diagnostic  sign  of 
incipient  epithelioma,  frequently  accompanies  tertiary  syphilis.  In 
some  cases  an  absolute  diagnosis  is  only  made  by  noting  the  disappear- 
ance of  the  local  lesion  following  the  administration  of  iodids,  the 
specific  treatment  of  tertiary  syphilis. 

1  Dental  Cosmos,  1892. 


522  INFECTIONS  OF  AND  FROM  THE  MOUTH. 

The  existence  of  tertiary  syphilis  is  of  great  clinical  importance  to 
the  dentist  in  that  a  condition  of  lessened  resistance  of  tissues  is  estab- 
lished, and  disease-processes  which  in  the  healthy  person  are  compara- 
tively circumscribed,  in  the  syphilitic  run  a  riotous  course.  A  septic 
pericementitis  by  extension  may  involve  a  wide  area  of  periosteum, 
leading  to  extensive  maxillary  necrosis. 

Tuberculosis  of  the  Mouth. — The  bacillus  of  tuberculosis,  under 
favorable  conditions,  develops  in  the  tissues  of  the  mouth,  producing 
its  characteristic  lesions.  Finding  a  suitable  soil,  such  as  is  furnished 
by  the  heredity  which  predisposes  to  phthisis  pulmonalis,  the  bacillus 
may  find  entrance  to  the  deeper  tissues  from  the  mucous  membrane  of 
the  mouth  and  excite  tuberculosis  in  the  deep  structures,  the  bone,  etc. 
What  part  is  played  by  local  oral  and  dental  lesions  in  tuberculosis  of 
distant  parts,  by  establishing  pathways  for  the  entrance  of  the  bacilli 
into  the  circulation,  is  at  present  conjectural,  but  that  such  infections 
occur  is  very  probable. 

Actinomycosis. — The  condition  produced  by  the  development  of 
the  ray-fungus,  the  actinomycosis,  in  the  lower  jaw  and  cervical  regions 
of  cattle  and  swine — lump-jaw — is  not  unknown  in  human  beings. 

Miller  ^  gives  203  cases  reported  in  German  medical  literature  be- 
tween 1886  and  1891.  In  at  least  120  of  these  cases  the  point  of 
entrance  of  the  fungus  was  found  to  be  in  the  region  of  the  mouth  or 
throat.  Actinomycosis-threads  have  been  repeatedly  found  in  the  saliva 
and  in  carious  teeth,  and  notably  in  the  tonsils.  Whether  the  path  of 
entrance  to  deeper  structures  is  ever  through  carious  teeth  is  undeter- 
mined, but  certainly  lesions  or  wounds  about  the  mouth  furnish  an 
entrance. 

General  Septic  Diseases  op  Dental.  Origin. 

The  effect  of  the  existence  of  dental  diseases  upon  the  body  at  large, 
particularly  as  regards  secondary  infection,  is  a  matter  increasing  in 
importance  as  the  possibilities  of  their  connection  are  made  out.  At 
present,  the  organisms  of  greatest  demonstrable  pathological  interest  are 
the  pyogenic  cocci.  The  almost  constant  presence  of  these  organisms  in 
the  mouth,  carried  thence  into  the  pharynx,  posterior  nares,  larynx,  and 
lungs,  furnishes  the  reason  for  the  pyogenic  inflammations  which  occur 
in  these  organs.  The  diplococcus  of  pneumonia,  a  frequent  organism, 
but  waits  a  favorable  opportunity  to  establish  high  inflammations  and 
fibrinous  exudations  in  the  lungs,  and  possibly  in  other  structures. 

The  most  important  clinical  associations  of  dental  with  general 
infections,  are  diseases  of  the  pericementum.  The  pulps  of  teeth, 
having  no  lymphatics,  do  not  appear  to  take   up  and   transmit  the 

^Dental  Cosmos,  1891. 


DENTAL  STERILIZATION.  523 

products  of  the  action  of  septic  organisms  ;  but  while  the  evidences 
of  such  absorption,  involvement  of  tlie  neighboring  lymphatics,  are  not 
present,  it  must  be  remembered  that  the  veins  may  transmit  the  poison, 
and,  in  addition,  may  perhaps  convey  organisms  from  a  diseased  but 
still  vital  pulp  to  distant  parts.  When,  however,  the  pulp  is  dead  and 
the  pericementum  is  invaded,  there  is  no  doubt  of  general  infection 
from  this  local  source.  More  or  less  septic  intoxication  is  a  common 
attendant  upon  severe  septic  apical  pericementitis,  and  septicaemia  ac- 
companied by  inflammation  of  the  neighboring  lymphatic  glands  is 
of  sufficient  frequency  to  emphasize  the  need  of  the  vigorous  antiseptic 
treatment  recommended  in  all  of  these  cases. 

Pysemia  is  far  more  uncommon.^  Pyogenic  organisms,  gaining  access 
to  the  blood-current  from  the  local  source  of  infection,  establish  sup- 
puration in  distant  parts  ;  in  other  parts  of  the  bone,  or  in  other  bones 
(osteomyelitis),  in  the  lungs,  meninges  and  substance  of  the  brain.  One 
case  ^  has  been  reported  where  abscess  of  a  toe,  ear,  and  forearm  ceased, 
and  recovery  took  place  after  treatment  and  filling  of  septic  root-canals. 
Several  cases  are  tabulated  by  the  same  author  in  which  extensive 
necrosis  and  death  resulted  from  pyemic  infection  from  septic  peri- 
cementitis. Some  of  these  cases  recorded  were  associated  with  acute, 
some  with  chronic  septic  pericementitis. 

In  addition  to  the  usual  pyogenic  cocci.  Miller  has  isolated  several 
forms  of  cocci,  bacilli,  and  spirilla,  forming  products,  which,  if  injected 
into  the  circulation  of  animals,  cause  death  from  septicaemia  in  from 
hours  to  days.  As  many  of  these  forms  may  be  brought  into  relation 
with  deep  parts  by  the  anatomical  conditions  created  by  pulp-death, 
the  possibilities  of  many  types  of  infection  via  pulpless  teeth  are 
evident. 

The  possibilities  of  infections  through  the  conditions  established  in 
the  several  forms  of  pyorrhoea  alveolaris  should  not  be  forgotten. 

The  pockets  formed  by  the  soft  tissues  overhanging  lower  third  mo- 
lars whose  eruption  is  imjjeded  invite  the  passage  of  septic  organisms  to 
deep  parts.     Local  pyogenic  infections  are  common  in  these  cases. 

Dental  Sterilization. 

It  must  ever  be  borne  in  mind  that  the  dental  operator  constantly 
works  in  a  field  of  infection,  and  unless  extraordinary  precautions  be 
taken  every  instrument  which  touches  this  field — the  fingers  of  the 
operator,  his  mirrors,  glasses,  napkins,  rubber-dam,  rubber-dam  clamps 
— becomes  immediately  infected  as  soon  as  it  is  brought  in  contact  with 
the  mouth  of  the  patient.  The  likelihood  of  infection  varies  with  the 
patient   and    the    particular    instruments ;    mouth-mirrors,  rubber-dam 

1  Miller,  Dental  Cosmos,  1891.  2  ji^i^ 


524  INFECTIONS  OF  AND  FROM  THE  MOUTH. 

clamps,  scalers,  and  all  instruments  used  in  the  treatment  of  pulp- 
canals,  are  likely  to  become  more  promptly  and  extensively  infected 
than  other  instruments.  Again,  the  forms  of  the  instruments  determine 
whether  or  not  increased  opportunity  is  given  for  the  retention  of  infec- 
tive material.  The  fingers  of  the  operator  may  be  the  medium  through 
which  infective  material  is  transferred  from  one  patient  to  another. 
Infection  may  be  carried  from  superficial  areas  of  the  mucous  mem- 
brane of  the  month,  from  the  enamel  and  the  saliva,  into  deeper  struc- 
tures, where  conditions  are  favorable  for  the  development  of  sepsis. 

The  scheme  for  dental  sterilization,  therefore,  includes  the  steriliza- 
tion of  the  operator,  instruments,  apparatus,  appliances,  etc.,  used  in 
operations,  and  the  sterilization  of  the  field  of  operation  prior  to 
operating. 

THE    OPERATOE. 

Extreme  personal  cleanliness  upon  the  part  of  an  operator  is  clearly 
the  first  step  in  asepsis.  The  best  class  of  dentists  are  exceedingly  neat 
as  regards  personal  habits  :  daily  bathing,  care  of  the  nails  and  of  the 
skin,  and  immaculate  linen,  form  as  much  a  part  of  the  day's  labor  as 
dental  operations  per  se.  The  virtues  of  soap  and  water,  wherever  they 
may  be  applied,  are  regarded  as  a  very  important  item  in  preventing 
infection. 

Linen  which  has  been  boiled  prior  to  wearing  may  be  regarded  as 
safely  sterile ;  so  that  the  matter  of  personal  sterilization  relates  to  the 
hands,  particularly  to  the  finger-nails.  The  space  under  the  nails  is  a 
favorable  habitat  for  many  organisms,  notably  the  pyogenic  cocci,  the 
staphylococcus  pyogenes  aureus  being  commonly  present  in  this  situation. 

It  has  always  been  advised  that  the  finger-nails  be  trimmed  short, 
and  be  made  smooth  to  avoid  mechanical  injury  to  the  soft  tissues  of 
the  patient.  Since  the  advent  of  aseptic  and  antiseptic  surgery  these 
precautions  have  an  additional  significance ;  nails  kept  short  and  smooth 
may  be  more  readily  cleansed  than  if  long  and  ill-kept.  The  nails 
should  be  cut  with  a  sharp  knife-blade  so  that  they  nowhere  project 
beyond  the  tips  of  the  finger.  Their  mechanical  cleansing  should  be 
done  with  smooth  instruments,  not  sharp  knife-blades  ;  the  latter  produce 
rough  surfaces,  which  furnish  spaces  for  lodgement  of  bacteria.  There  is 
but  one  effective  method  of  washing  beneath  the  nails  ;  it  is  that  followed 
by  the  general  surgeon  :  after  dipping  the  soap  in  water  as  hot  as  can  be 
borne  by  the  hands,  all  of  the  finger-nails  should  be  made  to  scrape  the 
soap  until  the  spaces  under  the  nails  are  filled  with  soap.  After  this, 
coarse  hand-brushes  are  used  to  scour  every  part  of  the  hands  with  soap 
and  water  as  hot  as  can  be  borne.  Special  nail-brushes  are  next  used 
to  scrub  beneath  the  nails,  driving  out  piecemeal  the  soap-masses  there. 
The  general  surgeon  continues  the  scrubbing  until  the  nails  are  scrupu- 


DENTAL  STERILIZATION.  525 

loiisly  clean.    The  soap  usually  used  is  Castile,  or  soap  made  from  palm 
oil,  etc. ;  but  antiseptic  soaps  may  be  substituted  with  advantage. 

Sterilization  of  the  cleansed  hands  is  insured  by  immersing  them  in 
antiseptic  solutions,  such  as  a  1  :  1000  solution  of  mercuric  chlorid.  The 
iiands  should  be  sterilized  after  treating  each  patient.  If  the  patient 
dismissed  have  possessed  an  unusually  septic  mouth,  or  have  been  a 
syjthilitic,  for  exam])le,  the  time  for  hand-cleansing  and  sterilization  is 
to  be  prolonged ;  if  syphilitic,  every  instrument  used  is  transferred  to 
separate  vessels  containing  antiseptic  solutions,  and  the  hands  arc  viewed 
iis  highly  infected  >  they  are  scrubbed  with  mercuric  chlorid  solutions 
to  prevent  personal  infection  or  the  carriage  of  infection. 

STERILIZATION    OF   APPARATUS. 

The  scrupulous  cleanliness  of  the  operating-chair,  whose  head -rest 
should  receive  frequent  changes  of  boiled  linen  coverings,  metallic  parts 
rubbed,  and  general  covering  cleansed  ;  the  cleansing,  polishing,  and 
sterilizing  of  cuspidores  ;  the  changing  of  lining  coverings  U})on  instru- 
ment-tables, etc.,  are  part  of  the  general  scheme  of  sterilization.  The 
floor  of  the  operating-room  also  requires  attention ;  instead  of  being 
covered  with  carpet,  it  is  preferable  to  have  it  made  of  jmrquetry 
material,  lacquered  hard  wood,  over  which  rugs  are  laid,  Avhich  may 
be  removed  from  the  room  for  cleansing,  the  floor  proper  being  scrubbed. 

Glassware,  such  as  tumblers,  may  be  effectually  sterilized  by  boiling. 
Linen  napkins  are  also  sterilized  in  the  same  manner.  Napkins  used 
about  the  mouth  are  certain  to  become  infected,  so  that  their  boiling 
should  be  prolonged  at  least  fifteen  minutes.  For  many  operations  it  is 
preferable  to  substitute  strips  of  muslin  for  linen  napkins,  which  after 
being  used  may  be  thrown  away. 

If  a  hydraulic  saliva-ejector  be  used,  the  glass  mouth-tubes  should 
be  changed  for  each  person,  a  sterilized  tube  being  immediately  sub- 
stituted as  soon  as  a  patient  leaves  the  chair.  These  tubes  should 
receive  prolonged  boiling  before  a  second  use.  At  the  close  of  each  day 
a  large  cup  should  be  filled  with  an  antiseptic  solution,  which  is  to  be 
drawn  through  the  tubing  of  the  ejector  to  keep  it  in  a  reasonably 
aseptic  condition. 

Rubber-dam  may  be  sterilized  by  boiling  water,  but  it  is  more  safe  and 
cleanly  to  use  a  new  piece  for  each  patient.  The  possibilities  of  infec- 
tion through  this  medium  are  great,  particularly  in  syphilitic  cases. 

STERILIZING    INSTRUMENTS. 

The  sterilizing  of  instruments  comprises  their  mechanical  cleansing 
and  the  use  of  germicides  ;  steam  heat  and  antiseptic  drugs  are  both 
employed  for  this  purpose.     Steam  heat  being  the  most  convenient  and 


526  INFECTIONS  OF  AND  FROM  THE  MOUTH. 

certain  sterilizing  agent,  is  used  wherever  it  cannot  produce  injury  to 
instruments. 

All  instruments  should  be  kept  in  a  highly  polished  condition,  being 
rubbed  with  crocus  cloth  at  the  end  of  each  day's  use.  Excavators, 
explorers,  and  pulp-canal  cleansers  should  be  mechanically  freed  from 
visible  foreign  matter  by  rubbing  their  points  with  a  wire  brush.  A 
wire  brush  should  be  used  to  cleanse  all  excavating-burs  w^hich  have 
been  in  use.  To  sterilize  the  mechanically  cleansed  instruments  they 
are  boiled  in  water  to  which  2  per  cent,  of  sodium  carbonate  has  been 
added  to  prevent  rusting. 

Mouth-mirrors,  of  which  there  should  be  several,  require  special 
care.  Their  edges  aiford  favorable  lodging-places  for  bacteria,  and 
hence  they  require  long  boiling.  Miller  ^  found  that  the  usual  antiseptic 
solutions  used  cold  acted  as  very  imperfect  sterilizers,  but  at  the  tem- 
perature of  boiling  their  efficacy  was  markedly  increased. 

Extracting-forceps  require  careful  mechanical  cleansing  and  pro- 
longed boiling  after  each  use,  for  perhaps  more  cases  of  infection,  and  of 
many  kinds,  have  resulted  from  dirty  forceps  than  from  all  other  causes 
combined. 

STERILIZING    THE    FIELD    OF   OPERATION. 

To  insure  sterilization  of  the  field  of  operation  antiseptics  should  be 
used  freely  about  the  mouth  prior  to  operating.  The  thoroughness  of 
the  sterilization  will  depend  in  great  degree  upon  the  personal  habits 
of  the  patient.  If  by  the  systematic  use  of  the  agents  and  measures 
described  under  the  prophylaxis  of  caries,  the  patient's  mouth  be  kept 
in  a  reasonably  aseptic  condition,  sterilization  of  the  oral  cavity  can  be 
accomplished  with  sufficient  readiness.  The  choice  of  antiseptic  will 
depend  in  great  degree  upon  the  state  of  oral  hygiene  ;  in  ill-kept 
mouths,  with  deposits  of  foreign  materials  about  and  between  the  teeth, 
on  the  gums  and  tongue,  much  more  active  and  penetrating  germicides 
will  be  required  than  if  the  parts  are  clean.  The  presence  of  ])utre- 
factive  decomposition  in  the  mouth,  made  evident  by  ill  odors,  amid 
which  that  of  hydrogen  sulfid  may  be  detected,  needs  for  its  treatment 
the  immediate  and  free  use  of  preparations  from  which  nascent  chloriu 
or  nascent  oxygen  may  be  disengaged.  No  operation  or  even  examina- 
tion should  be  begun  in  such  cases  before  a  claret-colored  solution  of 
potassium  permanganate,  or  a  strong  solution  of  hypochlorites  (medi- 
trina  diluted),  has  been  freely  used  by  the  patient.  Many  operators 
keep  a  stock  of  inexpensive  tooth-brushes  for  such  cases,  which  are 
thrown  away  after  the  patient  has  used  them,  who  is  directed  to  scrub 
the  teeth  well  with  brush  and  the  antiseptic  solution. 

^Dental  Cosmos,  1891. 


DENTAL  STERILIZATION.  527 

The  routine  practice  of  scaling  and  polishing  the  teeth  and  pre- 
scribing an  antiseptic  mouth-wash  prior  to  the  commencement  of  a 
series  of  sittings,  is  to  be  highly  commended.  To  sterilize  a  compara- 
tively clean  mouth  sufficiently  to  begin  dental  operations,  hvdro^-en 
dioxid  may  be  used  ;  it  should  be  held  in  the  niouth  and  pumped  about 
by  the  movements  of  the  lips  and  cheeks  for  a  minute  or  longer. 

If  ulcerations  or  inflammatory  conditions  exist,  the  sterilization  is 
to  be  prolonged,  using  such  agents  as  meditrina.  If  a  suspicion  of 
syphilis  exist,  not  only  should  the  mouth  be  freely  washed  with  strong 
antiseptics,  but  special  instruments  should  be  used,  preferably  an  old 
set,  kept  sterilized  and  used  only  in  special  cases.  If  the  hands  of  the 
operator  have  abrasions  or  irritated  spots,  they  should  be  covered  with 
collodion,  or,  better,  the  examination  should  be  referred  to  one  whose 
skin-surface  is  unbroken. 


SECTION  VII. 

DENTAL  PHARMACOLOGY  AND  DENTAL 
MATERIA  MEDICA. 


DENTAL    PHARMACOLOGY. 

A  DENTAL  materia  medica  includes  a  description  of  the  agencies 
which  are  employed  in  the  treatment  of  oral  diseases  ;  dental  pharma- 
cology considers  the  mode  of  action  and  composition  of  these  substances 
and  agencies.  The  intelligent  use  of  drugs,  as  of  any  therapeutic 
resource,  is  based  upon  a  primary  knowledge  of  their  chemical  and 
physical  properties,  together  with  a  familiarity  with  the  exact  nature  of 
the  altered  physiology  the  practitioner  is  called  upon  to  remedy.  A 
rational  therapeusis  is  founded  upon  the  utilization  of  the  specific  prop- 
erties of  remedial  agents  to  combat  morbid  conditions  whose  character 
has  been  clearly  determined. 

If  generalizations  be  made  of  the  several  disease-states  described  in 
the  body  of  this  volume,  it  will  be  seen  that  the  dental  practitioner 
meets  with  three  great  classes  of  conditions  requiring  treatment : 

First,  a  large  majority  of  diseases  of  the  teeth  and  associated  parts 
are  bacterial  in  origin — are  due  to  septic  influences  ;  hence  the  first 
group  of  agents  of  dental  practice  are  those  used  to  combat  septic  con- 
ditions, or  antiseptics. 

The  second  class  of  conditions  demanding  relief  are  those  in  which 
pain  is  a  prominent  symptom  ;  hence  the  second  class  of  agents  to  be  con- 
sidered are  those  used  for  the  relief  of  pain — anaesthetics  or  analgesics. 

The  third  group  of  conditions,  viewed  as  a  class,  comprises  those 
characterized  by  a  relaxation  of  soft  tissues  and  a  passive  dilatation  of 
their  bloodvessels  ;  hence  the  third  group  of  dental  remedies  is  that 
of  the  astringents,  or  substances  which  have  the  power  to  bring  about 
contraction  of  relaxed  parts. 

Nearly  all  of  the  agents  which  have  been  found  to  possess  distinct 
therapeutic  value  in  dentistry  may  be  placed  under  one  of  these  three 
heads,  although  an  agent  of  one  group  may  possess  properties  of  all 
three  classes. 

Some  few  of  the  drugs  and  agents  employed  in  dental  therapeusis 
cannot  be  properly  classified  under  any  of  the  three  heads  named,  but 

34  529 


530  DENTAL  PHAB3IAC0L0GY  AND  MATERIA  MEDICA. 

these,  as  well  as  all  other  therapeutic  agents,  may  be  incladed  under 
two  heads — stimulants  and  sedatives  ;  that  is,  all  agents  used  in  general 
or  special  medicine  are  employed  either  to  exalt  or  to  depress  some  one, 
or  more,  vital  functions  of  some  organ  or  tissues  of  the  body. 

Antiseptics. 

Antiseptics  are  agents  which  prevent  the  action  of  pathogenic  organ- 
isms or  of  their  products  upon  the  living  body.  Members  of  this  great 
group  differ  in  their  chemical  properties  and  mode  of  action.  Under 
the  head  of  antiseptics  are  grouped  sub-classes  of  remedies,  named  in 
accordance  with  their  mode  of  action  against  septic  influences.  They 
may  act  by  destroying  the  vitality  of  the  infective  organisms ;  a  sub- 
stance or  agency  having  this  power  is  termed  a  germicide.  They  may 
act  by  chemically  destroying  the  poisons  formed  by  bacteria  without 
necessarily  killing  the  organisms.  Conditions  may  be  established  in 
the  cells  of  the  body  which  inhibit  the  growth  of  organisms.  Any 
agent  which  has  the  power  to  remedy  an  existing  infection  is  called  a 
disinfectant.  It  is  seen,  therefore,  that  a  distinction  may  be  drawn 
between  an  antiseptic,  a  germicide,  and  a  disinfectant.  A  germicide  is 
both  antiseptic  and  disinfectant,  but  antiseptics  and  disinfectants  are 
not  necessarily  germicides.  Again,  an  antiseptic  acts  to  prevent  as 
well  as  remedy  infection  ;  a  disinfectant  implies  an  existing  infection. 
Under  this  head  should  be  grouped  deodorants,  agents  that  have  the 
power  of  destroying  objectionable  odors  which  arise  during  putrefactive 
processes,  and  from  other  sources.  A  true  deodorant  oj)erates  by 
chemically  destroying  the  malodorous  substance ;  for  example,  chiorin 
vapor  acts  as  a  deodorant  by  abstracting  the  hydrogen  from  such  a  sub- 
stance as  hydrogen  sulfid,  destroying  its  chemical  identity  and  therefore 
the  original  odor  : 

H2S  +  Cl2  =  2HCl  +  S. 

Bromin,  iodin,  and  nascent  oxygen  act  after  the  same  manner.  Most 
of  the  deodorants,  and  all  of  those  named,  are  active  antiseptics,  many 
of  them  germicides,  destroying  not  alone  the  organisms,  but  also  their 
waste-products.  Agents  such  as  carbolic  acid  and  the  cresols  are  not 
true  deodorants,  although  they  destroy  the  organisms  which  are  the 
primary  cause  of  the   offensive  odors. 

Nearly  all  of  the  antiseptics  employed  in  the  treatment  of  dental 
diseases  may  be  grouped  under  eight  heads  : 

r  Zinc  chlorid  ;  mercuric  chlorid  ; 
First.  Salts  of  metals     .    .    .    <        silver  nitrate,  citrate,  and  lac- 

l      tate  ;  copper  sulfate. 


ANTISEPTICS. 


531 


Second. 


Third. 


Fifth. 


Sixth. 


Seventh. 
Eighth. 


Alcohols  and  their  de- 
rivatives     


The  halogen  group  and 
their  compounds   .    . 


Fourth,      i 


Mineral  acids 


Organic  acids 


The  caustic  alkalies 


Solutions     from    which 
nascent     oxygen      is 


evolved. 


The  essential  oils 
Physical  agencies 


Ethyl  alcohol ;  methyl  alcohol, 
and  its  derivative  formal- 
dehyd  ;  phenyl  alcohol,  in- 
cluding all  allied  substances, 
such  as  creasote,  the  cresols, 
creolin,  and  lysol. 
^  lodin  and  its  pre])arations,  in- 
cluding iodoform,  noso})hcn, 
aristol,  iodol,  antinosin  ;  solu- 
tions from  which  nascent 
chlorin  may  be  evolved — 
hypochlorites  ;  bromin  is  not 
used  as  a  dental  disinfectant. 
'"  Sulfurous,  sulfuric,  hydro- 
chloric, chromic,  and  boric 
acids;  solutions  of  hyposul- 
fites,  which  act  by  virtue  of 
their  sulfite  radical,  may  be 
included. 

Trichloracetic,  lactic,  and  ben- 
zoic. 

Metallic  sodium  and  potassium 
in  alloy  (kalium-natrium)  . 
the  hydrates  and  carbonates 
of  sodium  and  potassium ; 
sodium  dioxid ;  aq.  ammoniae 
fort. 

Hydrogen  dioxid  in  Avatery 
and  ethereal  solutions  from 
3  per  cent,  to  25  per  cent, 
strength ;  solutions  of  so- 
dium dioxid  ;  potassium  per- 
manganate. 
^  Cajuput ;  cassia  ;  cinnamon  ; 
cloves  (and  eugenol) ;  eu- 
calyptus ;  gaultheria ;  myrtol ; 
and  thyme. 

Heat,  dry  and  moist. 


Each  of  these  groups  exhibits  distinct  modes  of  germicidal  action, 
in  accordance  with  their  chemical  properties. 

The  varied  conditions  under  which  bacteria  are  found  will  modify  the 
choice  and  application  of  antiseptics  and  germicides.     To  act  as  a  direct 


532  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

and  prompt  germicide  the  agent  mnst  be  brought  into  intimate  con- 
tact with  the  organisms.  There  are  physical  obstacles,  varying  under 
many  conditions,  which  antagonize  the  desired  end.  Many  forms  of 
bacteria  are  enclosed  in  a  resistant  coating  or  cell-wall ;  in  addition 
to  this,  several  forms  unite  into  large  colonies,  zooglea,  through  the 
medium  of  an  albuminous  excretion.  Even  under  favorable  conditions 
the  germicide  must  penetrate  the  mass  to  effect  sterilization.  In  addi- 
tion to  this,  the  offending  organisms  may  lie  deep  in  a  mass  composed 
of  fatty  and  albuminous  matter,  so  that  the  question  of  the  diffusibility 
of  the  antiseptic  is  an  important  one. 

"  An  antiseptic  agent  must  be  of  sufficient  strength  to  destroy  the 
disturbing:  bacteria.^ 

"  If  bacteria  develop  so  that  the  germicide  can  surround  or  easily 
penetrate  them,  they  are  more  readily  killed  than  when  they  develop 
in  mass  or  clump-forms,  and  are  surrounded  by  protective  matter,  as  we 
find  them  in  dental  caries,  root-canals,  etc.  In  this  state  a  stronger 
solution  of  the  disinfectant  is  generally  necessary,  and  a  longer  time  will 
be  required  for  the  agent  to  penetrate  the  mass  and  act  on  the  micro- 
organisms. 

"  An  agent  should  be  employed  that  will  not  limit  its  own  action  and 
thus  fail  to  reach  all  noxious  germs.  For  instance,  where  the  bacteria 
are  imbedded  in  albuminous  material,  oxidizing  agents,  as  hydrogen  di- 
oxid,  sodium  dioxid,  potassium  salts,  etc.,  will  disintegrate  and  perme- 
ate the  mass,  while  such  agents  as  bichlorid  of  mercury  and  silver 
nitrate  are  apt  to  combine  with  the  albuminous  material  and  coagulate 
it,  and  thus  limit  or  delay  their  own  action.  In  this  condition,  the  bi- 
chlorid may  act  as  an  antiseptic  and  restrain  growth  until  the  mercury 
is  partly  removed  by  the  action  of  ammonium  or  hydrogen  sulfid ;  then 
the  unkilled  germs,  or  spores,  will  again  develop  if  the  nutrient  material 
be  favorable  for  their  growth.  Diluted  solutions  of  such  an  agent,  how- 
ever, are  not  apt  to  cause  so  dense  a  coagulum  as  to  prevent  permeation 
throughout  the  mass ;  therefore  a  1  :  1000  or  1  :  2000  solution  of  bi- 
chlorid of  mecury  is  considered  most  desirable.  The  addition  of  5  parts 
of  tartaric  acid  to  1000  of  the  solution  assists  materially  in  preventing 
coagulation  by  bichlorid  solutions  (Laplace). 

"  Germicidal  agents  that  are  incompatible  should  not  be  used  together 
or  one  immediately  after  the  other.  Some  agents  become  inert  through 
chemical  reaction  when  brought  in  contact  with  putrefying  matter. 
Bichlorid  of  mercury,  especially  in  dilute  solutions,  is  rapidly  decom- 
posed by  sulfids,  alkalies,  ammonium  salts,  and  even  organic  matter. 

^  These  conditions  and  their  connection  have  been  well  summarized  by  L.  P.  Bethel, 
in  "Prize  Essay"  quoted. 


ANTISEPTICS.  533 

Therefore  its  use  as  a  dressing  for  root-canals  containing  putrescing 
material  is  of  doubtful  value, 

"  Very  volatile  antiseptics  should  not  be  used  where  a  continued 
action  is  desired,  as  in  root-canal  treatment. 

"Fresh  solutions  should  be  used.  Many  preparations  deteriorate 
with  age,  exposure,  etc. 

"Again,  the  potency  of  germicides  and  antiseptics  is  increased  by 
combining  medicaments.  For  instance,  the  germicidal  poAver  of  bichlorid 
of  mercury  is  increased  by  the  addition  of  hydrogen  dioxid,  benzoic 
acid,  etc.,  and  carbolic  acid  mixed  with  sulfuric  acid  increases  its 
efficacy.  When  these  and  other  disinfecting  agents  are  combined  with 
alcohol,  glycerin,  or  oil,  however,  the  germicidal  power  is  greatly  lessened. 

"  Laboratory  experiments  show  that  bichlorid  of  mercury  as  strong 
as  1  :  250  solution  in  absolute  alcohol,  or  1  :  50  in  glycerin,  does  not 
destroy  well-exposed  anthrax  spores  in  two  days'  time ;  but  a  1  :  1000 
solution  in  alcohol  plus  15  per  cent,  of  water,  or  1  :  500  in  glycerin 
plus  50  per  cent,  of  water,  will  destroy  them  in  twenty-four  hours. 

"  Oil  has  about  the  same  etfect  as  glycerin.  The  results  with  carbolic 
acid,  1  :  10  solution,  are  similar.  The  advantage  of  using  aqueous 
solutions  when  possible,  is  obvious. 

"  Laboratory  experiments  show  also  that  a  warm  or  hot  germicidal 
solution  is  more  effective  than  a  cold  one.  A  5  per  cent,  solution  of 
carbolic  acid  at  70°  F.  requires  one  month  to  kill  anthrax  spores.  Heated 
to  104°  F.  it  kills  them  in  about  six  hours ;  at  135°  F.,  in  one  hour 
and  a  quarter;  at  180°  F.,  in  fifteen  minutes.  A  1  :  1000  bichlorid 
of  mercury  solution  heated  to  115°  F,  is  equal  in  disinfecting  power  to 
a  1  :  500  solution  used  cold.  Experiments  made  with  various  bacteria 
to  determine  why  warm  or  hot  solutions  make  this  difference  seem  to 
indicate  that  not  only  is  the  vitality  of  the  bacteria  lowered,  but  the 
bacterial  cell  is  actually  enlarged  or  swollen,  probably  thus  increasing 
the  absorptive  surface, 

"  The  thermal  death-points,  with  moist  heat,  of  some  of  the  pus  micro- 
organisms, are — bacillus  pyocyaneus,  132°  F. ;  staphylococcus  pyogenes 
aureus,  136°  F. ;  citreus,  143°  F. ;  albus,  143°  F. ;  cereus  flavus,  134^ 
F. ;  cereus  albus,  134°  F. 

"This  points  out  the  advantage  of  using  hot  injections  of  water  or 
disinfectant  solutions  in  pyorrhoea  alveolaris,  pulpless  teeth,  antral  and 
other  diseases. 

"  For  germicides  to  act  most  effectively  the  field  of  operation  should 
be  as  thoroughly  prepared  as  possible  previous  to  their  application. 
For  example,  in  root-canal  treatment  some  instrumentation  should 
precede  the  application  of  the  dressing,  to  break  up  the  compact  masses 
and  permit  the  germicide  to  penetrate  to  the  organisms. 


534  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDIC  A. 

"  Grease  should  be  removed  by  aqua  ammonise,  equal  parts  of  ether 
and  alcohol,  or  chloroform  ;  and  all  other  foreign  substances,  which 
might  hinder  the  action  of  germicides  used,  should  be  removed." 

SALTS    OF    METALS    AS    ANTISEPTICS. 

The  salts  of  metals  are  used  in  watery  solutions  as  antiseptics — 
mercuric  chlorid  usually  in  1  :  1000  solution  ;  zinc  chlorid,  1  :  100 ; 
silver  nitrate,  1  :  100;  copper  sulfate,  1  :  100.  These  are  about  the 
strengths  in  which  these  agents  are  found  to  act  as  efficient  germicides ; 
but  in  the  interiors  of  teeth,  where  the  question  of  general  poisoning 
rarely  is  a  factor,  and  local  poisoning  only  a  remote  possibility,  these 
strengths  may  be  greatly  increased. 

Metallic  salts  act  as  germicides  by  chemically  destroying  protoplasm. 
When  a  metallic  salt,  in  sufficient  solution-strength,  is  brought  in  contact 
with  albuminous  material  an  obscure  chemical  change  occurs,  the  metal 
entering  into  combination  with  the  albumin  and  forming  a  substance 
which,  for  want  of  a  better  name,  is  called  an  albuminate  of  that  metal, 
an  opaque  body  rejilacing  the  transparent  gelatinous  albumin.  For 
example,  when  mercuric  chlorid  is  brought  in  contact  with  albuminous 
material,  such  as  serous  effusions,  the  serum  of  the  blood,  or  living 
cells,  animal  or  bacterial,  the  identity  of  the  albuminous  matter  is 
destroyed.  If  a  percentage  of  an  organic  acid,  say  tartaric  (Laplace), 
be  added  to  the  mercuric  solution  before  it  is  brought  in  contact  with 
the  albuminous  matter,  the  above  reaction  does  not  appear  to  occur. 
The  albuminate  of  mercury  thus  formed  is  decomposed  under  suitable 
conditions.  If  ammonium  sulfid  be  added  to  an  albuminate  of  mercury, 
mercuric  sulfid  is  formed  and  the  albumin  is  set  free.  This  reaction  is 
of  importance  as  regards  the  use  of  mercuric  chlorid  as  a  disinfectant 
where  sulfur  compounds  are  present,  as  in  putrefactive  fermentation, 
when  hydrogen  sulfid  is  formed,  a  similar  reaction  may  occur,  and  anti- 
septic effects  be  neutralized.  During  the  putrefactive  decomposition  of 
albumin  other  substances  than  II2S,  capable  of  decomposing  mercuric 
chlorid,  are  formed. 

Mercuric  chlorid  inhibits  the  vital  activity  of  living  cells,  even 
in  very  dilute  solutions.  A  solution  of  1  :  20,000  checks  the  move- 
ments of  spermatozoa ;  in  one  of  1  :  2000  it  acts  as  a  germicide  to  most 
micro-organisms,  although  several  forms  which  have  a  resistive  cell- 
wall  delay  the  germicidal  action.  The  spores  of  some  species  of  bacilli, 
notably  those  of  the  bacillus  anthracis,  are  markedly  resistant.  The 
precipitate  of  mercury  albuminate  which  occurs  interferes  with  the 
germicidal  action  of  the  solution  ;  the  addition  of  tartaric  acid  to  the 
mercury  solution  aids  its  germicidal  property  by  preventing  the  forma- 
tion of  mercurv  albuminate. 


ANTISEPTICS.  535 

While  all  of  the  metallic  salts  named  form  witli  solutions  of  albu- 
min ooagula,  or  albuminates  of  the  metals,  they  differ  in  the  rapidity  of 
the  chemical  change  and  in  the  character  of  the  coagulum.'  "  Capillary 
tubes  containing  a  mixture  of  albumin  and  20  per  cent,  of  glycerin,  the 
glycerin  being  added  to  prevent  the  drying  of  the  albumin.  One  end 
of  the  tube  was  sealed,  and  saturated  solutions  of  antiseptics  applied  at 
the  other  end  for  a  period  of  ten  days.  Contrary  to  the  belief  generally 
held,  silver  nitrate  was  found  to  effect  deep  coagulation,  the  coagulum 
becoming  dark  in  color  ;  zinc  chlorid  produced  complete  white  coagula." 

These  facts  are  of  great  importance,  since  they  prove  that  the  agents 
named,  instead  of  being  self-limited  in  action,  may  by  prolonged  con- 
tact affect  deeper  structures. 

Being  a  chemical  reaction,  there  is,  of  course,  as  pointed  out  by 
Kirk,^  a  quantitative  relationship  between  the  substance  acting  and  the 
substance  acted  upon. 

The  presence  of  a  coagulum  of  albumin  between  parts  to  be  acted 
upon  and  the  germicide  must  delay  and  interfere  with  the  free  diffusion 
of  the  germicide,  as  taught  by  Harlan  ;  but  if  the  germicide  be  present  in 
sufficient  amount,  it  will  diffuse  through  the  coagulum,  as  demonstrated 
by  the  experiments  of  Kirk  and  Truman. 

Secondary  changes  have  been  noted  in  the  coagulum  with  mercury. 
The  coagulum  of  zinc  chlorid  is  very  resistant  and  appears  to  possess 
permanent  antiseptic  properties.  The  coagulum  of  silver  nitrate  under- 
goes chemical  changes  :  the  albuminate  of  silver  is  reduced  to  an  oxid, 
and,  if  brought  in  contact  with  acids,  forms  corresponding  salts  of  silver. 
For  example,  in  contact  with  lactic  acid  silver  lactate,  a  persistent 
antiseptic,  is  formed. 

These  agents,  used  in  sufficient  strength,  form  coagula  with  the 
protoplasm  of  cells,  coagulating  intercellular  albuminous  material  and 
forming  an  eschar — /.  e.,  they  are  caustics. 

ALCOHOLS    AND    THEIR    DERIVATIVES    AS    ANTISEPTICS. 

The  alcohols  and  their  derivatives  also  act  as  germicides  by  effecting 
coagulation  of  albuminous  bodies.  They  differ  in  the  rapidity  of  their 
action  and  in  their  germicidal  strength.  The  cresols,  trikresol  having 
the  greatest  antiseptic  power,  carbolic  acid  next,  and  ethylic  alcohol 
least.  Formaldehyd  in  watery  solution  is  the  most  promptly  acting  and 
penetrating  agent  of  this  group. 

HALOGEN    DERIVATIVES    AS    ANTISEPTICS. 

The  halogen  group  has  its  activity  represented  by  the  chemical  affinities 
of  iodin  and  chlorin.    These  agents  abstract  hydrogen  from  organic  com- 

1  Truman,  Proc.  Academy  of  Stomatology,  1894.  ^  Dental  Cosmos,  1893. 


536  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

pounds,  and  thus  destroy  their  identity.  While  it  is  certain  that  they  act 
as  germicides,  destroying  the  vitality  of  protoplasm,  their  principal  field 
of  usefulness  is  in  rendering  innocuous  the  products  of  bacterial  de- 
composition. The  iodin  derivatives  named  under  this  head  are  supposed 
to  set  iodin  free  when  brought  in  contact  with  infected  tissue,  the  iodin 
acting  as  a  persistent  disinfectant.  Their  activity  is  gauged,  therefore, 
by  the  amount  of  iodin  set  free — i.  e.,  by  the  amount  present  and  the 
looseness  of  its  combination. 

ACIDS   AS   ANTISEPTICS. 

The  mineral  acids  effect  the  chemical  destruction  of  animal  sub- 
stances, inorganic  and  organic,  with  which  they  are  brought  in  contact. 
They  differ  in  their  activity  in  this  direction  and  in  the  depth  of  their 
action.  For  example,  sulfuric  acid  quickly  forms  a  black  eschar  upon 
tissue,  chromic  acid  penetrates  deeply  into  tissues  to  which  it  is  applied. 
The  milder  acids,  such  as  boric  acid,  appear  to  have  no  escharotic  action. 

The  strong  mineral  acids  abstract  the  potassium,  sodium,  and  cal- 
cium elements  from  tissues  with  which  they  are  brought  in  contact,  in 
addition  to  destroying  albumin.  The  organic  acids  have  a  similar 
action. 

Solutions  of  hyposulfites  act  by  virtue  of  the  sulfite  radical,  SO2, 
which  abstracts  the  elements  of  water  from  organic  matter,  forming 
sulfurous  acid,  HgSOg.  The  sulfite  radical  formed  by  burning  sulfur 
acts  in  the  same  manner. 

CAUSTIC   ALKALIES   AS   ANTISEPTICS. 

The  caustic  alkalies  chemically  destroy  albuminous  matters  with 
which  they  are  brought  in  contact.  They  combine  with  the  fatty  acids 
produced  during  putrefactive  decomposition  of  tissues,  and  form  soaps. 
The  hydrates  of  sodium  and  potassium  are  the  most  active.  These 
substances  are  formed  when  the  alloy  of  sodium  and  potassium  is  brought 
in  contact  with  organic  matter.  The  alloy  abstracts  hydroxyl,  HO, 
from  organic  matter,  and  produces  secondary  decompositions  by  the 
hydroxids  of  the  metals  which  are  formed.  Sodium  dioxid  (NagOj), 
in  contact  with  organic  matter,  sets  free  its  loosely  held  oxygen  atom, 
and  the  sodium  ox  id  left  quickly  abstracts  water  from  the  organic 
matter,  forming  sodium  hydroxid : 

NagOg  4-  organic  matter  =  NgO  +  O  + . 
Na^O  +  H2O  =  2NaH0, 

which  acts  as  above  described. 

Aq.  ammonise  fort,  acts  by  virtue  of  its  affinity  for  water  and  fatty 
acids. 


ANESTHETICS.  537 

THE    ESSENTIAL   OILS   AS   ANTISEPTICS. 

The  essential  oils  possess  in  varying  degree  the  property  of  destroy- 
ing bacteria  ;  while  it  is  probable  that  they  effect  a  change  in  albuniinons 
substances  akin  to  coagulation,  it  has  not  yet  been  clearly  demonstrated. 
Certainly  they  act  as  poisons  when  brought  in  contact  with  protoplasmic 
substances.  Their  germicidal  power  varies,  that  of  the  oils  of  thyme 
and  cinnamon  being  greatest ;  that  of  cloves  (eugenol  also)  is  less 
marked.  Placed  in  the  roots  of  pulpless  teeth,  they  diffuse  very 
gradually  through  the  contents  of  the  dentinal  tubules.  They  may 
cause  distinct  staining  of  the  tooth,  a  proof  of  their  diffusion. 

PHYSICAL    AGENCIES    AS    ANTISEPTICS. 

Of  the  physical  agencies,  the  only  available  germicide  is  heat.  It 
produces  coagulation  of  albuminous  matter,  and  is  thus  antiseptic. 
The  degrees  and  conditions  of  heat  necessary  to  complete  germicidal 
action  vary  as  to  the  mode  of  applying  the  heat  and  also  upon  the 
nature  of  the  organisms  present.  Moist  heat  is  a  much  more  effective 
germicide  than  is   dry  heat. 

A  degree  of  heat  fatal  to  any  mature  organism  may  not  destroy  the 
vitality  of  its  spores.  The  spores  of  some  bacilli  resist  a  temperature 
of  boiling  water  for  several  hours.  Most  organisms,  however,  are 
promptly  killed  by  water  at  a  temperature  of  212°  F. 

Anesthetics. 

An  anaesthetic  is  any  agent  which  prevents  the  perception  of  pain. 
A  condition  of  insensibility  to  pain,  or  tactile  sensitivity,  may  be 
induced  in  three  ways  :  first,  by  paralyzing  or  destroying  the  terminals 
of  sensory  nerves  through  which  impressions  of  pain  are  conducted — 
that  is,  by  abolishing  reception ;  secondly,  by  interfering  with  or  pre- 
venting the  transmission  of  such  impressions  after  their  reception  ; 
thirdly,  by  so  acting  upon  the  perceptive  centre  of  the  brain  that  its 
function  is  held  in  abeyance — i.  e.,  by  abolishing  perception. 

Agents  Avhich  have  the  poAver  of  lessening  the  consciousness  of  pain 
are  grouped  under  the  heads  of  anodynes,  analgesics,  and  obtundents. 
Tlie  term  anaesthesia,  as  originally  used,  indicated  a  conditit)n  of  insensi- 
bility attended  by  loss  of  consciousness ;  hence  the  term  anaesthetic  is 
usually  employed  to  designate  such  substances  as  derivatives  of  ethane, 
notably  cthylic  oxid  or  ether  ;  derivatives  of  methane,  such  as  methyl 
trichlorid  or  chloroform  ;  and  nitrous  oxid  gas. 

An  anodyne  is  an  agent  acting  upon  the  pain-perceptive  centre 
of  the  brain  in  such  a  manner  that  perception  of  pain  is  benumbed 
or  lost ;  the  term  refers  to  abolishing  existing  pain,  as  by  the  action  of 
opium  derivatives. 


538  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDIGA. 

An  analgesic  is  an  agent  which  either  prevents  or  subdues  pain,  and 
may  act  upon  any  portion  of  the  sensory  tract. 

Under  the  head  of  obtundents  are  included  those  agents  which  are 
applied  locally  to  benumb  the  terminals  of  sensory  nerves. 

Hypnotics  act  as  analgesics  by  inducing  sleep,  during  which  common 
sensation  is  in  abeyance. 

The  typical  general  anaesthetics  are  those  named  above ;  chloroform 
as  the  representative  methane  derivative ;  ether,  the  ethane  deriva- 
tive ;  and  nitrous  oxid,  the  asphyxial  anaesthetic. 

Chloroform  and  ether  act  as  general  anaesthetics  by  abolishing  the 
functions  of  the  centres  of  consciousness  in  the  cerebrum,  and  that  of 
pain-perception.  "  They  probably  enter  into  loose  combination  with, 
the  protoplasm  of  the  cortex  of  the  brain,  producing  a  temporary  fixa- 
tion, and  interfere  with  the  process  of  oxidation  and  reduction  upon 
which  the  functions  of  these  cells  depend."  ^ 

The  effects  of  these  agents  are  progressive  :  the  higher  cerebral  func- 
tions are  first  abolished  ;  next  the  special  sense-perceptions  ;  then  reflex 
activities ;  until,  finally,  the  centres  which  preside  over  the  vital  func- 
tions of  respiration  and  circulation  are  involved,  and  if  administration 
be  carried  beyond  this  point,  death  results. 

In  general  terms,  these  anaesthetic  agents  and  their  kindred  may  be 
said  to  be  dangerous  to  life  in  proportion  to  their  vapor-density.  The 
greater  their  vapor-density,  the  longer  they  remain  in  the  body. 

Nitrous  oxid,  under  the  usual  conditions  of  administration,  induces 
general  anaesthesia  by  the  exclusion  of  oxygen  from  the  lungs  and  the 
accumulation  of  carbon  dioxid  in  the  blood ;  in  addition,  it  has  a 
specific  anaesthetic  action,  as  unconsciousness  and  anaesthesia  are  in- 
duced when  the  nitrous  oxid  administered  is  mixed  with  oxygen. 
Nitrous  oxid  is  to  be  regarded  as  the  only  entirely  safe  general 
anaesthetic. 

The  number  of  fatalities  attending  the  use  of  chloroform,  the  list  being 
particularly  large  in  connection  with  its  administration  for  tooth-extrac- 
tion, is  sufficiently  extensive  to  absolutely  contraindicate  its  use  in  that 
connection.  The  danger  is  twofold  :  first,  the  erect  posture,  which 
favors  and  appears  to  precipitate  syncope  ;  secondly,  the  partial  anaesthe- 
sia. More  deaths  are  recorded  as  occurring  in  connection  Avith  partial 
than  with  full  chloroform-narcosis ;  probably  under  partial  anaesthesia 
the  reflexes  are  not  entirely  lost,  and  a  condition  of  profound  shock 
ensues  upon  performing  minor  operations.^  Death  under  chloroform  in 
some  cases  is  due  to  paralysis  of  respiration  ;  in  others,  of  the  circulation. 
In  many  of  the  cases,  when  respiration  ceases  and  the  heart  continues 

^  Lauder  Brunton,  Croonian  Lectures,  1888. 
^  See  Brunton,  Pharmacology  and  Therapeutics. 


ANAESTHETICS.  539 

to  beat,  life  may  be  preserved  if  artificial  respiration  be  maintained  long 
enoujrh  for  the  body  to  rid  itself  of  the  chloroform-vapor. 

Representative  anodynes,  agents  benumbing  the  pain-perce})tion 
centre  of  the  brain,  are  morphia  and  several  of  the  coal-tar  derivatives. 
These  agents  probably  act  in  a  manner  similar  to  that  noted  in  connec- 
tion with  the  general  anaesthetics,  by  forming  loose  combinations  with 
the  protoplasm  of  nerve-cells.  Many  of  them  affect  the  nervous  paths, 
and  when  locally  applied  to  sensory  nerve-terminals  reduce  their  func- 
tion, so  that  they  may  act  as  analgesics  under  all  three  heads  named. 

The  coal-tar  derivatives  are  chemically  the  analogues  of  the  vegetable 
alkaloids ;  that  is,  they  are  substitution-products  of  ammonia.  By  re- 
placement of  the  several  hydrogen  atoms  of  the  ammonia  base  pre- 
determined properties  may  be  conferred  upon  compounds.  Begin- 
ning with  replacement  by  a  phenyl  radical  and  adding,  for  example, 
the  amesthetic  basis  methyl,  analgesic  substances  are  produced.  For 
example,'  ^Hg,  ammonia,  may  have  two  of  its  hydrogen  atoms  replaced 
by  other  radicals  : 

N — H         =  anilin 
\H 


N — H  =  phenyl  acetamide  or  acetanilid,  an  analgesic  agent. 

\COCH3 

The  remaining  hydrogen  atom  may  be  replaced  by  the  anaesthetic 
radical  CH3,  methyl,  increasing  the  analgesic  power  of  the  compound  : 

/C,H,  ..  .  • 

N — COCH3  forming  methyl  acetanilid,  or  exalgin. 

\CH3 

Displacements  and  replacements  in  such  comparatively  simple  bodies 
may  be  made,  changes  of  physiological  properties  following  upon  changes 
of  chemical  composition. 

These  agents  have  the  power  of  paralyzing  the  paths  of  pain-con- 
duction. 

Equally  instructive  observations  may  be  noted  in  connection  with 
local  anaesthetics,  those  agents  which  possess  the  power  of  benumbing 
the  terminals  of  sensory  nerves.  Excluding  such  agents  as  volatile 
hydrocarbons,  rhigolene,  ethyl  and  methyl  chlorid,  in  which  specific 
paralyzing  action  is  masked  by  the  intense  cold  produced  by  their 
application,  and  inducing  analgesia,  it  will  be  seen  that  the  best-known 
^  Brunton,  Croonian  Lectures,  1888. 


540  DENTAL  PHABMAGOLOGY  AND  MATERIA  MEDIGA. 

and  most  active  local  ansesthetics  are  all  related  to  one  another  in  chem- 
ical composition.  These  agents  are  atropia,  homatropin,  tropacocain, 
cocain,  and  eucain. 

Atropia  is  a  compound  of  tropic  acid  with  tropein,  a  tropate  of  tro- 
pein ;  either  of  these  substances  alone  possesses  no  analgesic  power,  but 
the  combination  is  slightly  analgesic.  If,  however,  tropein  be  combined 
with  benzoic,  instead  of  tropic  acid,  benzoyl  tropein  is  formed  (hom- 
atropin),  which  possesses  marked  anaesthetic  properties. 

The  next  member,  tropacocain  (benzoyl  pseudo-tropein),  bears  a 
chemical  relationship  to  the  former,  and  has  additional  ansesthetic  power. 

Cocain  is  chemically  benzoyl  methyl  ecgonin  ;  when  boiled  it  is  split 
up  into  methylic  alcohol,  benzoic  acid,  and  ecgonin.  The  ansesthetic 
properties  reside  in  the  benzoyl  methyl,  and  are  much  more  marked 
than  in  compounds  in  which  the  methyl  radical  is  absent. 

In  eucain,  the  next  member,  benzoyl  and  methyl  are  both  present, 
the  latter  multiplied  and  in  several  combinations,  so  that  the  ansesthetic 
properties  are  greater  than  those  of  cocain. 

If  ethyl  instead  of  methyl  be  combined  with  benzoyl  ecgonin,  an 
ansesthetic,  cocethylen,  is  formed. 

The  benzoyl  derivatives  of  other  substances,  such  as  morphia,  have 
ansesthetic  properties. 

The  induction  of  analgesia  by  some  local  ansesthetics  is  preceded  by 
a  stage  of  irritation. 

The  phenyls  are  all  local  ansesthetics,  but  many  of  them  combine 
actively  with  the  albuminous  portions  of  tissues  and  act  also  as  caustics. 

The  benzoyl  derivatives  mentioned  act  not  only  as  paralyzants  of 
nerve-terminals,  but,  if  applied  or  injected  about  the  trunk  of  a  nerve, 
induced  analgesia  in  the  distribution  of  that  nerve.  They  paralyze 
nerve-centres  to  which  they  are  applied. 

The  essential  oils  possess  the  power  of  paralyzing  sensory  nerve- 
terminals,  inducing,  first,  marked  irritation ;  this  eifect  is  absent  when 
they  are  applied  to  the  dental  pulp,  a  tissue  in  which  tactile  sensitivity 
is  normally  absent. 

Astringents. 

Astringents  are  chemical  agents  which,  when  applied  to  swollen  vital 
tissues,  cause  their  contraction  without  their  destruction.  Many  of 
them,  however,  if  used  in  sufficient  strength,  immediately  destroy  the 
vitality  of  tissues  to  which  they  are  applied  ;  for  example,  zinc  chlorid 
in  saturated  solution  is  a  powerful  caustic ;  in  10  per  cent,  solution  is 
an  active  astringent  ;  and  in  1  per  cent,  solution  acts  as  a  stimulant. 
The  reason  for  this  is  readily  seen  from  a  study  of  its  mode  of  action. 

Astringents  are  divided  into  vegetable  and  mineral ;  the  vegetable 


ASTEINGENIX  541 

astringents  owe  their  property  to  the  tannic  acid  contained  in  them. 
The  mineral  astringents  are  mainly  salts  of  iron,  copper,  lead,  and 
zinc — acetates,  sulfates,  and  chlorids.  Astringents,  with  but  few  ex- 
ceptions, act  by  causing  more  or  less  coagulation  of  all)uminous  fluids 
and  a  shrinkage  of  the  tissues  in  which  they  are  contained,  and,  with 
the  exception  of  subacetate  of  lead  and  nitrate  of  silver,  do  not  cause 
contraction  of  bloodvessels  ;  tannic  and  gallic  acids  cause  dilatation  of 
vessels.^  It  will  be  seen,  therefore,  that,  with  the  exception  of  silver 
nitrate  and  lead  acetate,  all  astringents  are  positively  contraindicated  in 
active  inflammation.  Their  sphere  of  usefulness  is  limited  to  states 
of  venous  congestion  with  effusion  ;  for  example,  in  such  conditions  as 
chronically  tumid  gums,  the  use  of  an  active  vegetable  astringent  will 
cause  constringing  of  the  swollen  tissues  and  dilatation  of  the  arteries, 
with  an  increased  flow  of  blood ;  the  weakened  veins  will  receive  sup- 
port, and  stagnation  be  relieved. 

These  substances  diff'er  in  effect  in  proportion  to  their  affinity  for 
albumin,  and  the  strength  in  which  they  should  be  used  will  depend 
upon  this  affinity  ;  for  example,  zinc  chlorid  or  silver  nitrate  used  in 
strength  greater  than  20  per  cent,  will  combine  with  protoplasm  and 
cause  tissue-death. 

In  combining  two  or  more  remedies  regard  should  be  paid  to  the 
chemical  reactions  which  may  occur  between  them  and  alter  their 
nature  ;  drugs  which,  mixed  together,  produce  undesirable  combinations 
are  termed  incompatibles.  It  may  easily  happen  in  the  practice  of  den- 
tistry that  such  mixtures  may  be  made  and  produce  ill-results;  for 
example,  if  sulfuric  acid  be  used  in  connection  with  steel  instruments  in 
dental  canals,  and  preparations  containing  tannic  acid  be  afterward 
applied,  a  black  tannate  of  iron  forms,  staining  the  dentin  ;  or,  again,  if 
attempts  be  made  to  bleach  discolored  dentin  with  nascent  chlorin  in 
teeth  containing  gold  fillings,  auric  chlorid  may  form  and  cause  per- 
manent staining.  The  following  list  from  Hare  Ms  a  useful  summary 
of  common  incompatibles  : 

First.  An  acid  should  never  be  combined  with  an  alkali. 

Second.  An  acid  should  not  be  added  in  any  quantity  to  a  tincture. 

Third.  Alkalies  should  not  be  combined  with  the  alkaloids. 

Fourth.  Potassium  chlorate  should  not  be  ordered  to  be  rubbed  up 
with  tannic  acid  or  any  other  organic  substance  capable  of  oxidation,  as 
it  will  explode.     Permanganate  of  potassium  is  subject  to  the  same  rule. 

Sixth.  Iron  is  incompatible  with  tannic  acid,  as  it  forms  a  tannate 
of  iron,  or  ink.  As  all  the  vegetable  astringents  contain  tannic  acid, 
none  of  them  should  be  used  with  iron,  except  chiretta  and  calumba. 

Seventh.  Tannic  acid  should  never  be  added  to  solutions  of  alkaloids. 

^  Brunton,  Pharmncology  and  Therapeutics.  ^  Pmctknl  'Tlierapeutics. 


542  DENTAL  PHARMACOLOGY  AND  MATERLi  MEDICA. 

Eighth.  Alcoholic  solutions  of  camphor  and  similar  resinous  sub- 
stances are  incompatible  with  water. 

Ninth.  Fluid  extracts  are  incompatible  with  water,  as  the  addition 
of  water  will  cause  a  precipitate. 

Tenth.  All  salts  not  acid,  but  alkaline  in  reaction,  are  decomposed 

by  acids. 

Eleventh.  All  salts  which  are  acid  are  decomposed  by  alkalies. 

Twelfth.  All  vegetable  acid  salts  are  altered  by  mineral  acids  and 
are  decomposed  by  alkalies. 

Thirteenth.  lodin  and  iodids  should  not  be  given  with  alkaloids. 

Fourteenth.  Corrosive  sublimate,  the  salts  of  lead,  iodid  of  potas- 
sium, and  nitrate  of  silver  should  always  be  prescribed  alone. 

Fifteenth.  Cocain  and  borax  when  added  together  form  an  insoluble 
borate  of  cocain.     Boric  acid  and  cocain  do  not  form  this  substance. 

Electricity  in  Dental  Therapeutics. 

Electricity  is  utilized  in  dental  therapeusis  for  its  physical,  chemical, 
and  physiological  effects.  For  physical  and  chemical  effects  the  con- 
stant or  galvanic  current  alone  is  employed ;  for  physiological  effects 
both  interrupted  (faradic)  and  constant  (galvanic)  currents  are  applied ; 
the  former  rarely,  the  latter  frequently. 

Physical  Effects. — The  physical  properties  utilized  are  the  correla- 
tion of  electric  currents  into  light  and  heat.  Small  lamps  operated  at  an 
electric  pressure  of  8  to  10  volts,  placed  in  proper  relation  to  reflecting- 
mirrors,  are  used  to  transilluminate  teeth,  to  determine  the  vitality  of 
their  pulps.  A  somewhat  less  voltage  is  used  in  connection  with  an 
appropriate  hand-piece  and  a  loop  of  line  platinum  ware  to  generate  a 
high  degree  of  heat  in  the  latter — an  electrocautery.  This  is  used  to 
destroy  the  peripheral  portions  of  the  dentinal  processes  in  cases  of 
excessive  hypersensitivity  of  dentin. 

"  If  a  long  copper  point  be  placed  in  a  pulp-canal,  and  the  electro- 
cautery be  brought  in  contact  with  its  end,  sufficient  heat  is  transmitted 
through  the  copper  to  dry  the  walls  of  the  canal.  If  the  canal  be  filled 
with  an  antiseptic  oil  prior  to  inserting  the  copper  point,  the  oil  may 
be  vaporized  and  driven  into  the  tubules.  If  wax  or  paraffin  be  placed 
in  the  canal,  the  copper  point  set  in  position,  and  heat  applied,  the 
substance  will  be  melted  and  will  run  into  all  the  interstices  of  the 
canal.  The  metallic  point  is  permitted  to  remain  as  the  central  canal- 
filling."  ' 

Physiolog-ical  Effects. — An  induced  interrupted  current  was  used 
by  Bon  will  as  early  as  1859  to  paralyze  the  reaction  of  the  nerves 
about  the  root  of  a  tooth,  so  that  the  latter  could  be  extracted  pain- 
'  Gramm,  Dental  Cosmos,  vol.  35. 


ELECTRICITY  IN  DENTAL   THERAPEUTICS.  543 

lessly.  The  same  device  has  been  used  to  allay  the  irritability  of  the 
dentinal  processes  and  permit  painless  cutting  of  dentin. 

Kapidly  interrupted  currents  have  been  applied  to  relieve  the  symp- 
toms of  pulpitis  and  acute  pericementitis. 

A  moistened  electrode  applied  to  the  back  of  the  neck,  the  other 
pole  upon  the  cheek,  will  tend  to  cause  contraction  of  the  blood- 
vessels. 

They  appear  to  reduce  also  the  pain  referred  to  the  seat  of  disease. 
The  eifects,  however,  are  much  less  marked  than  when  a  galvanic  cur- 
rent is  employed.  The  latter  is  useful  in  those  cases  of  trifacial 
neuralgia  in  which  there  is  an  irregular  contraction  of  arteries.  The 
galvanic  current,  30-50  elements,  will  bring  about  a  uniform  contrac- 
tion of  the  vessels.  This  measure  is  merely  palliative,  not  curative,  so 
that  in  cases  of  reflex  neuralgia  of  dental  origin  it  precedes  and  follows 
removal  of  the  cause. 

Chemical  Effects. — The  electrolytic  power  of  the  galvanic  current 
is  utilized  in  dental  therapeutics.  If  a  current  such  as  is  obtainable 
from  the  cataphoretic  apparatus,  with  a  maximum  voltage  of  35  to  40, 
be  passed  through  vital  tissues,^  the  electro-positive  elements  of  the 
tissues,  potassium,  sodium,  calcium,  and  hydrogen,  appear  at  the  nega- 
tive pole,  and  acids,  chlorin,  and  oxygen  at  the  positive  pole.  "  It 
follows  that  if  the  positive  electrode  be  composed  of  metal,  it  will  be 
corroded  by  the  action  of  the  chlorin  and  acids,  and  the  negative  will 
remain  unacted  upon  and  smooth."  If  the  electrode  be  of  zinc  or  of 
copper,  the  oxychlorids  of  those  metals  are  formed,  and  exercise  their 
chemical  effects  upon  organic  matter  with  which  they  are  brought  in 
contact ;  hence  they  act  as  germicides  and  caustics.  At  the  negative 
pole  the  caustic  alkalies  form  and  destroy  tissue,  if  the  application  be 
sufliciently  prolonged.  The  eflPects  may  be  graded  according  to  the 
current-intensity  and  duration  of  the  application.  Effective  electrolysis 
is  excited  Avith  45  milliamperes  of  current.^ 

If  the  negative  pole  be  applied  to  the  gum  over  a  tooth,  and  the 
positive  pole  to  the  back  of  the  neck  and  its  position  shifted  from  time 
to  time,  alkalies  may  be  liberated  in  the  tissues  and  cause  effects  ranging 
from  effective  counter-irritation  to  the  actual  breaking-down  of  indurated 
tissue,  or  the  removal  of  hyperplasia. 

If  the  positive  pole  be  placed  in  a  root-canal  and  the  negative  pole 
upon  some  other  point,  fluids  of  the  tooth  or  tissues  about  the  apex  of 
the  root  (if  the  electrode  be  carried  into  them)  are  decomposed,  and 
the  substances  formed  act  upon  the  tissues.  If  a  zinc  electrode 
be  used,  the  germicidal  and  caustic  zinc  oxychlorid  is  formed,  as  above 
noted. 

^  Bartholow's  Medical  Electricity.  ^  Ibid. 


544  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

Another  important  property  of  the  constant  current  is  utilized  in  den- 
tal therapeutics,  viz.,  the  power  of  such  a  current  to  cause  the  passage 
through  an  intervening  resistance,  of  substances  in  solution  from  the  posi- 
tive toward  the  negative  pole — cataphoresis,  or  electrical  osmosis.  This 
property  is  well  illustrated  by  an  experiment  of  Morton's.  A  glass 
vessel  containing  a  porous  septum  dividing  it  into  two  chambers,  has 
placed  in  one  of  the  chambers  a  solution  of  starch,  in  the  other  a  solu- 
tion of  iodin.  If  now  the  positive  pole  of  a  galvanic  combination  be 
placed  in  the  iodin  solution,  and  the  negative  in  the  starch  solution,  the 
iodin  is  caused  to  pass  more  quickly  through  the  septum,  and  the  blue 
coloration  of  the  iodin  reaction  with  starch  at  once  appears. 

Through  the  aid  of  such  a  current,  with  appropriate  electrodes  and 
under  proper  insulation,  solutions  of  drugs  may  be  caused  to  pass  along 
the  conducting  paths  of  the  dentin — i.  e.,  through  their  tubuli ;  medica- 
ments may  be  carried  from  the  surface  of  the  gum  into  the  pericemen- 
tum, etc.  This  principle  is  utilized  in  the  treatment  of  hypersensitive 
dentin,  for  which  special  apparatus  is  necessary,  so  that  the  voltage  may 
be  raised  by  small  fractions,  the  dental  pulp  being  peculiarly  intolerant 
of  electric  currents  abruptly  applied. 

Bleaching-agents,  hydrogen  dioxid  solutions,  may  be  quickly  driven 
into  the  deeper  portions  of  discolored  dentin  by  this  means. 

With  suitable  electrodes,  cocain  solutions  may  be  driven  in  about  the 
roots  of  teeth  to  render  the  operation  of  tooth-extraction  painless. 

Hypodermatic  Medication, 

Local  ansesthetics — cocain,  eucain,  and  tropacocain — are  used  by  the 
hypodermatic  method  to  render  painless  the  operation  of  tooth-extrac- 
tion. Certain  precautions  should  be  observed  in  their  use.  The  field 
of  operation  should  be  sterilized  to  prevent  the  entrance  of  pathogenic 
organisms  to  deep  parts.  The  syringe  and  all  of  its  parts  must  be  care- 
fully sterilized,  as  must  also  the  solution  employed.  Cocain  solutions 
require  the  addition  of  an  antiseptic.  Eucain  solutions  may  be  sterilized 
by  boiling.  The  minimum  physiological  dose  of  the  drug  should  be 
employed,  suspended  in  a  large  volume  of  fluid.  The  injection  should 
be  made  in,  not  under,  the  maxillary  periosteum.  Injections  should 
never  be  made  in  the  loose  tissue  of  the  corium,  as  annoying  swellings 
result  and  anaesthesia  fails.  a  ^ 


ACETANILID— ACIDS.  545 


DENTAL    PHARMACOPCEIA. 

The  agents  used  in  dental  therapeutics  and  their  modes  of  action 
have  been  considered  under  the  head  of  dental  pharmacology,  so  that 
further  classification  is  unnecessary.  The  therapeutic  application  of 
any  agent  may  be  determined  by  noting  its  description  under  the 
alphabetical  headings  of  this  section,  and  then  turning  to  the  portion 
on  pharmacology  where  general  and  specific  group-properties  are  dis- 
cussed. 

ACBTANILID   (AnTIFEBRIN). 

Its  name,  acetanilid  or  phenyl  acetamide,  is  derived  from  its  chemical 
composition,  graphically  represented  in 

\C2H3O. 

Acetanilid. 

It  is  an  amide,  a  substitution-product  of  ammonia,  one  hydrogen  atom 
of  ammonia  being  replaced  by  phenol,  and  one  by  acetyl,  or  it  may  be 
regarded  as  anilin, 

N— H 

Anilin. 

in  which  a  hydrogen  atom  is  displaced  by  acetyl.  It  is  a  whitish  crys- 
talline powder,  slightly  pungent,  without  odor ;  sparingly  soluble  in 
water,  and  freely  soluble  in  alcohol,  ether,  and  chloroform.  Combined 
with  ammonium  carbonate,  the  mixture  is  known  as  ammonol.  Com- 
bined with  caffein  citrate  and  sodium  bicarbonate,  the  preparation  is 
called  antikamnia. 

It  relieves  pain  and  reduces  temperature,  and  in  large  doses  depresses 
the  action  of  the  heart.  The  dose  is  from  3  to  15  grs.  In  combination 
with  ammonium  carbonate  its  depressing  action  on  the  heart  is  almost 
neutralized.  Used  in  painful  affections,  in  neuralgia,  and  to  lessen  the 
pains  of  pulpitis  and  pericementitis  ;  grs.  v.,  repeated  until  15  grs.  are 
taken.  It  has  been  used  locally  as  a  mild  antiseptic  to  raw  surfaces, 
instead  of  the  usual  antiseptic  powders. 

Acids, 
acid,  acetic,  iic2h3o2. 
The  glacial  anhydrous  acid,  C^H^O^,  is  used  as  a  caustic. 
Acid,  Trichloracetic. — The  trichloracetic  acid  is  the  form  in  which 

35 


546  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

acetic  acid  is  used  in  dentistry,  the  three  hydrogen  atoms  of  the  radical 
being  replaced  by  chlorin,  HC2CI3O2.  This  is  a  colorless  and  very  deli- 
quescent substance.  It  coagulates  albumin  promptly,  hence  it  is  caustic. 
It  is  used  deliquesced  as  a  caustic  to  destroy  gum  overhanging  developing 
lower  third  molars,  and  to  destroy  vital  remnants  of  pulps  in  the  roots 
of  teeth.  Diluted,  it  is  used  as  an  astringent  in  pyorrhoea  pockets  and 
to  soften  the  deposits  of  calculi. 

ACID,  AESENIOUS. 

The  anhydrous  arsenious  acid,  or  arsenic  trioxid,  AS2O3,  a  white 
crystalline  powder,  is  insoluble  in  cold  water,  but  partially  soluble  in 
an  excess  of  boiling  water,  when  arsenious  acid,  HgAsOg,  is  formed, 
a  feebly  acid  substance.  It  is  soluble  in  hydrochloric  acid  and  freely 
soluble  in  alkalies. 

Combined  with  a  fresh  magma  of  ferric  hydrate,  the  soluble  arsen- 
ites  are  converted  into  insoluble  arsenite  of  iron.  This  fact  is  made 
use  of  to  prevent  the  absorption  of  arsenic  which  has  been  taken  into 
the  stomach.  Evacuation  of  the  contents  of  the  stomach  should 
follow. 

Applied  to  tissues,  arsenic  causes  violent  inflammation,  followed  by 
profound  degenerative  changes ;  the  application  is  attended  by  much 
pain.  The  inflammation  excited  by  its  presence  prevents  the  absorp- 
tion of  any  but  a  very  minute  amount.  It  is  used  in  dentistry  for  the 
sole  purpose  of  devitalizing  the  pulps  of  teeth.  It  is  made  into  paste 
and  applied  to  the  pulp ;  or  cotton-fibre  is  rolled  in  the  paste,  dried, 
and  small  pieces  of  it  applied. 

^i.  Acid,  arsenosi,  "] 

Cocain.  hydrochlorid.,  or  V  da  gr.  x  ; 

Morphinse  acetat.,  / 

01.  cinnamomi,  or 

01.  caryophylii,  q.  s.  ft.  paste. 

ACID,  BENZOIC,  CqH^CO^H.. 

Benzoic  acid  is  prepared  by  heating  gum  benzoin  ;  the  acid  sublimes 
in  pearly  white  plates.  Faintly  soluble  in  water ;  freely  soluble  in 
ether,  chloroform,  and  strong  alcohol.  Locally  applied  it  is  slightly 
stimulant.  It  is  markedly  antiseptic  and  non-poisonous,  hence  is 
a  valuable  ingredient  in  mouth-washes. 

ACID,  BORIC,  II3BO3, 

is  slightly  soluble  in    cold   water ;   soluble  in    strong  alcohol   and    in 
glycerin.     A    non-toxic  antiseptic ;    it   is    useful    as    an    ingredient    in 


ACIDS.  547 

mouth-waslies.  Combined  with  sodium  sulfite,  to  evolve  sulfur  dioxid, 
SO^,  for  bleaching  purposes  (see  Sodium  Sulfite). 

ACID,  CARBOLIC. 

Phenylic  alcohol,  phenyl  hydroxid,  CgH^HO,  when  pure,  is  colorless 
and  crystalline  ;  odor  is  distinctive.  Becomes  fluid  at  95°  F.  The  addi- 
tion of  glycerin  renders  it  fluid.  It  is  soluble  in  a  great  excess  of  water, 
a  3  per  cent,  solution  being-permanent.  It  is  readily  soluble  in  ether, 
chloroform,  alcohol,  glycerin,  and  the  essential  oils.  It  coagulates  albu- 
minous matter,  hence  is  caustic ;  it  acts  as  a  germicide  in  virtue  of  the 
same  property  ;  locally  applied,  it  is  an  anaesthetic.  Used  in  dentistry  in 
full  strength  to  obtund  the  hypersensitivity  of  dentin,  to  relieve  the  pain 
of  pulpitis  ;  as  an  antiseptic  in  carious  cavities,  in  putrescent  pulps,  in 
root-canals,  and  in  septic  pericementitis.  Used  as  a  caustic  for  canker 
sores,  stomatitis  ulcerosa. 

In  3  per  cent,  solution  it  is  used  as  an  irrigating  antiseptic  and  to 
keep  sterilized  instruments  in,  prior  to  using  them. 

ACID,    CHROMIC,  CrOg. 

Chromic  anhydrid,  when  deliquesced  or  dissolved  in  water,  becomes 
H^,CrO^,  or  chromic  acid.  A  powerful  caustic,  rarely  used  in  dentistry. 
Has  been  used  as  a  dentinal  obtundent,  and  as  a  caustic  in  sluggish  ulcers. 
Its  present  uses  in  dentistry  are  in  |^  of  1  per  cent,  solution  as  a  harden- 
ing fluid  for  histological  work,  and  in  galvanic  batteries. 

ACID,    GALLIC, 

does  not  coagulate  (see  Tannic  Acid),  but  causes  contraction  of 
bloodvessels,  hence  is  not  used  as  a  styptic  locally,  but  when  the  inter- 
nal administration  of  a  haemostatic  is  indicated.  Given  in  pill-form  ; 
dose,  grs.  2-20. 

ACID,    HYDROCHLORIC,    HCl. 

Rarely  used  in  dentistry.  Used  to  supply  deficiency  of  HCl  in 
stomach  and  to  check  fermentative  processes  there.  It  rapidly  decalci- 
fies the  hard  tissues  of  the  teeth. 

ACID,    LACTIC,    CsHgOg. 

A  syrupy  liquid  freely  soluble  in  water.  It  is  the  acid  of  fermenta- 
tive origin  which  decalcifies  the  teeth  in  the  progress  of  caries.  It  has 
the  power  of  dissolving  fibrinous  exudates,  and  is  used,  therefore,  to 
remove  the  false  membrane  in  diphtheria.  In  20-50  per  cent,  solution 
it  is  used  to  soften  deposits  of  calculi  in  cases  of  pyorrhoea  alveolaris, 
and  as  a  stimulant  astringent  to  the  engorged  soft  tissues  about  the 
parts. 


548  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

ACID,  XITEIC,  HXO3. 

The  strong  acid  is  used  as  a  caustic  application  to  canker  sores.  Its 
application  is  productive  of  pain,  so  that  carbolic  acid  is  preferred  for 
this  purpose.  Used  to  touch  abraded  spots  of  hypersensitive  dentin 
upon  the  occlusal  faces  of  the  teeth.  As  decalcification  results,  such 
spots  are  to  be  excavated  and  filled. 

ACID,   OXALIC,   C2H2O4, 

should  be  plainly  marked,  as  its  crystals  are  readily  mistaken  for 
those  of  magnesium  sulfate  (Epsom  salt).  Used  to  liberate  chlorin 
from  calcium  hypochlorite,  in  the  process  of  bleaching  discolored  dentin 
(Truman). 

ACID,    PHOSPHORIC. 

The  ortho-acid,  HgPO^,  in  solution,  is  the  fluid  ingredient  of  zinc- 
phosjjhate  cements. 

ACID,   SALICYLIC,    HC7H5O3, 

is  contained  in  oil  of  gautheria  (wintergreen).  It  may  be  obtained 
from  this  source,  or  be  made  synthetically  by  decomposing  sodium 
salicylate  with  hydrochloric  acid.  Is  slightly  soluble  in  cold,  freely 
soluble  in  hot  water.  Soluble  in  alcohol.  Borax  in  solution  aids  the 
solubility  of  salicylic  acid,  hence  their  conjoined  use  in  mouth-washes. 
In  solution  strength  of  1  :  200,  salicylic  acid  destroys  most  of  the  forms 
of  bacteria  found  in  the  mouth.  Its  principal  use  in  dentistry  is  as  an 
ingredient  of  mouth-washes. 

ACID,    SULFURIC,    HgSO^. 

Sulfuric  acid  is  used  in  dental  therapeutics  in  50  per  cent,  solution, 
mainly  to  gain  access  to,  to  enlarge,  and  sterilize  root-canals  so  minute  as 
to  refuse  entrance  to  fine  instruments.  It  is  used  full  strength  as  a  destruc- 
tive obtundent  in  cases  of  hypersensitive  dentin.  In  weak  solution,  10 
per  cent.,  it  is  used  to  neutralize  the  free  alkali  in  teeth  left  after 
applications  of  sodium  dioxid  or  sodium-potassium.  The  same  solution 
is  used  to  soften  the  deposits  in  cases  of  pyorrhoea  alveolaris,  to  remove 
dead  bone,  and  as  an  astringent.  It  is  a  solvent  of  the  calcium  salts  of 
the  teeth  and  destroys  organic  matter  by  a  process  of  chemical  dehy- 
dration. 

Acid,  sulfuric,  aromatic,  is  a  mixture  of  sulfuric  acid  in  alcohol, 
spirit  of  cinnamon,  and  tincture  of  ginger,  in  strength  of  7|-  per  cent. 
By  the  action  of  the  sulfuric  acid  on  alcohol  a  portion  of  the  latter  is 
oxidized,  forming  an  ether.  Its  uses  are  those  of  dilute  sulfuric  acid, 
and,  in  addition,  it  has  marked  stimulating  properties.  It  is  used  full 
strength  in  treating  pyorrhoea  pockets,  as  a  calcic  solvent,  a  germicide, 


ACONITE.  549 

a  stimulant,  and  an  astringent.  It  is  used  to  dissolve  carious  bone  and 
to  stimulate  the  vital  parts  to  reparative  action. 

ACID,    SULFUROUS,    H^SOg, 

acts  as  a  bleaching-agent  by  a  process  of  reduction,  seizing  upon  the 
oxygen  of  the  pigment.  Is  used  as  a  bleaching-agent  for  discolored 
dentin.  It  is  generated  by  mixing  the  dry  powders  of  sodium  sulfite 
and  boracic  acid,  placed  in  contact  with  discolored  dentin,  water  is 
applied  and  sulfarous  acid  is  disengaged  (Kirk).  It  acts  as  a  deodorant 
and  antiseptic  in  the  same  manner  as  above  given. 

ACID,    TANNIC,    C27H22O17, 

is  readily  soluble  in  water,  alcohol,  and  glycerin.  It  is  the  astrin- 
gent principle  of  most  of  the  vegetable  astringents.  When  oxidized, 
as  when  tannic  acid  is  taken  into  the  body,  gallic  acid  is  formed.  It 
brings  about  a  rapid  coagulation  of  the  blood  with  a  contraction  of 
vessel-walls ;  hence  is  used  as  a  styptic  locally  in  powder.  In  solutions 
of  various  strengths  adapted  to  the  conditions,  it  is  applied  to  reduce 
the  passive  congestion  of  swollen  gums  and  tumid  mucous  membranes. 
Its  solution  in  glycerin  is  known  as  glycerite  of  tannin  ;  it  is  made  by 
dissolving  1  part  of  tannic  acid  in  4  parts  of  glycerin,  through  the  aid 
of  heat.  This  preparation  is  used  in  cases  of  swollen  and  passively 
congested  mucous  membranes ;  the  hygroscopic  glycerin  attracts  the  fluid 
exudates,  and  the  tannic  acid  causes  contraction  of  the  engorged  tissues. 
Tannic  acid,  in  combination  with  alum,  glycerin,  and  thymol,  is  used 
to  mummify,  and  harden  the  remnants  of  pulps  not  removable  by 
mechanical  means. 

ACID,  TRICHLORACETIC.     (See  Acid,  Acetic.) 

Aconite. 

Tincture  of  the  root,  tine,  aconiti  radicis ;  dose  1  to  5  drops ;  used  in 
one-drop  doses  to  reduce  the  pulsations  of  an  overacting  heart  in  acute 
inflammations.  Locally  used  in  combination  with  iodin  to  subdue  peri- 
cemental inflammation  : 

R.  Tr.  iodin.,  \  ^^_^ 

Tr.  aconiti  rad.,   J 
Sig.  Painted  on  gum,  over  the  affected  tooth. 

In  old  preparations  the  evaporation  of  the  alcohol  may,  by  concen- 
tration of  the  solution,  increase  the  volume-strength,  and  poisoning  may 
occur  if  used  freely.  Antidotes  are  cardiac  stimulants — ammonia, 
whiskey,  brandy.     The  physiological  antidote  is  atropia. 


550  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDIGA. 

AcONITINE 
is  the  alkaloid  of  aconite,  an  extremely  active  poison.     Its  dose  is 
T7o  S^*     -^^^  dental  use  is  in  ointment : 

^.  Aconitini,  gi'-  j  ? 

Cerat.  simp.,  SJ. — M. 

Sig.  To  be  rubbed  over  the  tissues  in  front  of  the  ear  to  relieve 
the  trismus-like  pains  which  may  attend  difficult  eruption 
of  lower  third  molars. 

Alcohol. 

Ethylic  alcohol,  CgHgHO,  or  ethyl  hydroxid,  95  per  cent,  alcohol : 
being  about  94  per  cent,  by  volume,  91  per  cent,  by  weight  of  ethyl 
hydroxid — i.  e.,  9  per  cent,  by  weight,  6  per  cent,  by  volume  of  water. 
Specific  gravity  at  60°  F.  0.820. 

Methyl  alcohol,  CH3HO,  methyl  hydroxid.  Whiskey  and  brandy 
containing  from  48  to  56  per  cent,  by  volume  of  ethyl  alcohol,  are  used 
as  diffusible  stimulants  in  cases  of  syncope  from  any  cause ;  dose, 
3SS-J.  Strong  alcohol  is  very  astringent,  and  is  antiseptic.  Being 
hygroscopic,  it  readily  takes  up  water ;  this  property  is  utilized  in  pro- 
ducing dryness  of  the  dentin  prior  to  inserting  fillings  and  canal-fill- 
ings. Both  ethyl  and  methyl  alcohols  are  used  as  solvents  for  several 
vegetable  gums  which  are  employed  in  both  laboratory  and  office  uses. 
(See  Lining  Varnishes.) 

PHENYL    ALCOHOL,    CgHgHO,   PHENYL    HYDROXID.     (See    Carbolic 

Acid.) 

Alum. 

Aluminum  potassium  sulfate,  Al2(S04)3,K2SO^  +  24H2O. 

Aluminum  ammonium  sulfate,  Al2(S04)3,(NH4)2S04  +  24H2O. 

It  is  the  potash-alum — aluminii  at  potassii  sulfas — which  is  usually 
employed  in  medicine.  It  is  a  colorless  salt,  soluble  in  about  fifteen  vol- 
umes of  cold  water,  and  in  three-quarters  of  a  part  of  hot  water.  It  has 
a  sweetish,  astringent,  and  acid  taste,  but  unless  the  specimen  contain 
free  acid,  alum  solutions  should  be  neutral  in  reaction.  Alum-exsi- 
catum — dried  alum — is  alum  whose  water  of  crystallization  has  been 
driven  off  by  heat,  forming  a  white  granular  powder. 

Solutions  of  alum  are  used  as  astringent  washes  in  cases  of  passive 
hypersemia  of  the  gum-tissue,  such  as  those  caused  by  the  presence  of 
salivary  calculi,  and  in  pyorrhoea  alveolaris.  It  should  be  ascertained 
that  the  alum  contains  no  excess  of  acid — that  is,  should  not  redden 
blue  litmus  paper — before  it  is  used.     Powdered  alum  is  a  powerful 


AMMONIUM— ANTIPYRIN.  551 

styptic,  and  may  be  used  on  cotton  tampons  for  the  relief  of  alveolar 
hemorrhage.  Alum  exsicatum  is  used  as  a  mild  caustic  to  exuberant 
granulations :  it  acts  both  as  a  caustic  and  astringent. 

Ammonium. 

Ammonium  hydrate,  NH^HO,  and  the  neutral  carbonate 
(NH3)2C03,  are  used  in  combination  with  oils  of  lemon,  pimento,  and 
lavender,  in  solution  of  alcohol  and  water  as  a  diffusible  stimulant, 
under  the  name  of  spiritus  ammonise  aromaticus.  Given  in  doses  of 
5ss-ij,  it  acts  as  a  prompt  cardiac  stimulant. 

Ammonium  nitrate,  NH^NOa,  is  the  salt  from  which  the  angesthetic, 
nitrogen  mouoxid  (nitrous  oxid),  is  disengaged. 

NH,N03+  heat  (350°-450°  F.)  =  N2O  +  211  f>. 

Ammonol  (see  also  Acetanilid) 

is  a  combination  of  acetanilid  with  ammonium  carbonate  ;  the  latter  is 
added  to  neutralize  the  depressing  effect  of  acetanilid  upon  the  heart. 
Dose,  grs.  v-x.  Used  in  neuralgic  conditions,  hemicrania,  tic  dou- 
loureux, and  to  benumb  the  pains  of  pulpitis  and  acute  pericementitis. 
It  is  frequently  very  effective  in  the  latter  affection. 

Amyl  Nitrite,  Amyl  Nitris,  CsHnNOa 

Dose,  1Uij-v.  It  is  dispensed  in  glass  pearls  containing  these  amounts. 
It  is  administered  by  inhalation.  It  depresses  the  inhibitory  apparatus 
of  the  heart ;  used  when  the  peripheral  bloodvessels  are  in  a  state  of 
marked  contraction,  it  causes  their  immediate  dilatation  ;  hence  is  used 
in  angina  pectoris,  to  relieve  the  spasmodic  contraction  of  the  heart  and 
vessels,  and  in  conditions  of  shock  with  pale  surface.  It  has  been 
suggested  as  an  antidote  to  chloroform,  when  the  conditions  named 
present,  but  as  it  is  also  the  antagonist  of  strychnia,  the  antidote  of 
chloroform,  its  use  must  be  guarded. 

Antipyrin 

is  phenyl-dimethyl-pyrazolon.  Irrespective  of  physiological  experi- 
ments, a  substance  having  the  chemical  composition  given  would,  at  the 
present  day,  be  known  to  have  the  power  of  reducing  pain  and  lessening 
temperature,  which  are  in  fact  its  uses.  Dose,  iii.-x  grs.  Antipyrin  is 
freely  soluble  in  water.  Small  doses  decrease,  large  doses  increase,  the 
reflex  activity  of  the  brain,^  the  cause  of  the  depression  being  due 
to  sedation  of  the  sensory  nerves  and  of  their  centres  in  the  spinal  cord. 
Applied  to  mucous  membranes  or  beneath  the  skin,  this  agent  is  a  power- 
'  Hare,  Practical  Therapeutics. 


552  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

fill  local  anaesthetic,  the  anaesthesia  lasting  often  for  several  days.  Bar- 
tholow  ^  and  Hare  both  agree  that  the  cardiac  depressing  action  of  anti- 
pyrin  is  over-rated,  being  only  marked  in  the  cumulative  action  of  the 
drug.  Its  antidotes  are  atropia  and  stimulants.  It  is  used  to  relieve 
the  pain  of  facial  neuralgia,  pericementitis,  and  acute  pulp-diseases. 

ArISTOL,    DiTHYMOL — Dl-IODID. 

Introduced  as  a  substitute  for  iodoform,  upon  the  assumption  that 
iodoform  acts  as  an  antiseptic  in  virtue  of  setting  free  iodin  when  brought 
in  contact  with  vital  tissues  ;  aristol  containing  twice  the  amount  of 
iodin,  should  have  greater  power ;  the  thymol  should  also  exercise  par- 
ticular antiseptic  action.  Reports  as  to  its  efficacy  are  contradictory. 
Upon  cocci  and  bacilli  aristol  has  less  power  than  iodoform  (Hare). 
It  is  used  in  dentistry  as  a  dressing  in  pulp-canals  which  have  con- 
tained putrescent  pulps  ;  its  value  as  a  persistent  antiseptic  in  these 
cases  is  masked,  owing  to  the  previous  or  simultaneous  use  of  other 
antiseptics. 

Borax,  NajBiO,  +  lOH^O.     Boric  Acid. 

Impure  borax  is  the  common  flux  of  the  dental  laboratory.  In  this 
state  it  sometimes  contains  borates  of  other  metals  than  sodium,  which 
may  cause  contamination  of  the  noble  metals  (Hiorns).  Pure  borax  is 
soluble  in  twelve  parts  of  water.  Saturated  solutions  are  used  as 
mouth-washes  in  conditions  of  stomatitis  (aphtliEe)  as  an  antiseptic.  It 
is  an  ingredient  of  Dobell's  solution,  which  is  used  as  an  antiseptic  wash 
in  catarrh  of,  and  empysema  of  the  antrum,  and  in  stomatitis  : 


I^.  Sodii  boratis,             \ 
Sodii  bicarbonatis,    J 

da 

r'y, 

Acidi  carbolici, 

gr.  XXX ; 

Glycerni, 

gj; 

Aquse  purse. 

Oij.— M 

S.  Used  warm,  as  a  spray. 

Boric  acid  is  a  useful  addition  to  antiseptic  mouth-washes.  Used 
dry,  on  aphthous  sores,  and  in  cases  of  cancrum  oris,  ulcerative  stoma- 
titis, etc.,  it  is  an  admirable  antiseptic.     An  ointment : 

^.  Ac.  boric,  .5j  ; 

Cerat.  alb.,  3j  ; 

Paraffin,  Sij  ; 

Ol.  amyg.  exp.,  fgij. — M. 

'  Materia  Medica  and  Therapeutics. 


BOROGLYCERIN— CALCIUM.  553 

is  a  useful  application  to  chapped  lips  and  in  herpes  labialis,  and  to 
prevent  cliapping  of  the  hands. 

BoROGLYCERIN  ^ 

is  made  by  mixing  62  parts  of  boric  acid  with  92  parts  of  glycerin,  in  a 
tarred  porcelain  capsule,  at  a  temperature  of  about  300°  F.  The  acid 
is  added  to  the  glycerin  gradually,  stirring  constantly  ;  when  the  mixture 
is  reduced  to  100  parts  it  is  poured  on  a  block  slightly  wet  with  petro- 
leum ;  when  dry  it  is  cut  in  blocks  and  kept  in  stoppered  bottles.  One 
ounce  of  these  blocks  is  added  to  one  ounce  of  glycerin  to  form  glycerite 
of  boroglycerin,  a  vehicle  for  carbolic  acid  and  other  substances  applied 
as  mouth-washes. 

Bromids. 

Potassium  broraid,  gr.  v-3J. 

Sodium  bromid,  gr.  v-3j. 

Used  as  sedatives  when  the  cerebral  circulation  is  overfull,  as  in 
teething  children  and  in  acute  pericementitis.  Applied  locally  to  reduce 
the  excessive  irritability  of  the  mucous  membrane  of  the  soft  palate  and 
fauces.  Will  relieve  the  form  of  migraine  accompanied  by  flushed  face 
and  injected  eye.  Will  quiet  the  irritability  of  hysterical  dental  patients. 

Oaffein. 

Caffein,  the  active  principle  of  coifee  ;  thein,  the  active  principle  of 
tea,  and  that  of  guarana,  are  chemically  identical.  Used  in  combination 
with  acetanilid  in  the  mixture  called  antikamnia  (which  see)  to  counter- 
act its  depressing  and  increase  its  analgesic  effects. 

Oajuput  Oil.     (See  Oils,  Antiseptic.) 
Calcium. 
Calcium  oxid  (lime)  in  solution  in  water  has  been  used  as  an  antacid 
mouth-wash. 

Calcium  carbonate  (precipitated  chalk)  is  used  as  an  ingredient  of 
dentifrices,  and  as  an  antacid,  rubbed  over  the  teeth  at  night,  to  neutral- 
ize the  acids  causing  caries  and  erosion,  and  to  lessen  the  hypersen- 
sitivity of  dentin. 

Calcium  hypochlorite  in  mixture  with  calcium  chlorid,  is  used  as  a 
bleaching-agent  for  discolored  dentin.  Chlorin  is  liberated  by  the 
action  of  dilute  organic  acids.^ 

The  hypophosphites,  phosphates,  and  lacto-phosphates  have  been  ad- 
ministered to  increase  the  amount  of  calcium  salts  in  dentin  in  which 

1  Hare,  Practical  Therapeutics.  ^  Truman. 


554  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

these  salts  were  supposed  to  be  deficient ;  it  has  never,  however,  been 
demonstrated  that  they  have  any  effect  in  this  direction. 
Calcium  sulfate  (gypsum)  calcined,  is  plaster  of  Paris. 

Camphor. 

Camphor  liniment  (soap,  camphor,  oil  of  rosemary,  alcohol,  and 
water)  is  used  with  friction  over  the  masseter  muscle  to  relieve  the  tem- 
porary spasms  caused  by  difficult  eruption  of  lower  third  molars. 

Camphor  spirits,  a  few  drops  in  a  glass  of  water,  is  used  to  lessen 
the  irritability  of  the  soft  palate  and  fauces,  to  permit  manipulation  of 
those  structures. 

0  AMPHO-PHENIQUE . 

A  fluid  substance  formed  by  the  combination  of  nearly  equal  parts 
of  carbolic  acid  and  gum  camphor,  said  to  be  a  definite  chemical  body 
having  the  formula  CgH^jO,  the  reaction  presumably  being 

C,oH,30  +  QH,HO  =  2C3H,,0. 

Camphor.      Phenyl  alcohol. 

It  possesses  the  antiseptic  and  anaesthetic  properties  of  carbolic  acid, 
and,  in  addition  the  stimulant  property  of  camphor.  It  does  not  pro- 
duce an  eschar ;  it  is  insoluble  in  water.  Its  uses  are  those  of  carbolic 
acid  in  general ;  but  it  has  not  the  depressing  effect  of  that  agent  upon 
the  vitality  of  tissues  to  which  it  is  applied.  It  is  used  in  full  strength 
for  hypersensitivity  of  dentin,  to  sterilize  infected  and  purulent  pulps, 
and  as  a  stimulant  antiseptic  application  to  the  walls  of  chronic  alveolar 
abscesses.  It  may  be  used  as  a  stimulating  antiseptic  application  to 
pyorrhoea  pockets  after  removal  of  the  deposits  and  washing  with 
hydrogen  dioxid. 

Cantharides  (Spanish  Flies). 

An  active  principle  called  cantharidin,  is  extracted  from  the  crushed 
bodies  of  the  beetle,  cantharis  vesicatoria.  It  is  used  in  plaster,  charta 
cantharadis,  or  in  collodion,  collodion  cum  cantharide,  to  produce  blis- 
tering. A  blister  placed  in  front  of  the  ear  or  beneath  the  ear  is  a 
counter-irritant  of  service  in  relieving  the  pains  of  pulpitis  and  peri- 
cementitis, after  local  therapeusis  has  been  applied.  A  small  blister 
applied  to  the  gum,  at  some  distance  from  an  affected  root,  is  useful  in 
cases  of  sluggish  pericementitis  of  the  chronic  type. 

Capsicum. 

Depending  upon  the  strength  in  which  they  are  used,  preparations 
of  capsicum  are  stimulants  or  irritants,  and  are  used  to  stimulate  slug- 
gish local  circulation  or  as  counter-irritants. 


CHLORAL  HYDRATE— COCAIN.  555 

Tr.  capsicum  may  be  used  alone,  or  as  tr.  capsici  et  myrrhse  ;  either 
is  added  to  water  until  cloudiness  appears ;  used  as  a  stimulant  wash  in 
cases  of  atonic  affections  of  the  gum-tissues,  and  to  hasten  the  separa- 
tion of  sequestra  of  bone.  Powdered  capsicum  and  ginger,  made  into 
packet-form,  in  small  muslin  bags,  and  called  capsicum  bags,  are  useful 
as  counter-irritants  in  acute  pulp-affections  and  in  chronic  pericemental 
disturbances.  ^   l^  riyrJ^^Ui--^   -^ 

Chloral  Hydrate.  C.HC130.h;o.  ^:CC^^<-  l^  ^^ 
The  syrup  of  chloral,  in  doses  of  fsj,  is  an  admirable  hypnotic  in  oi^-i^Cu^ 
cases  of  insomnia  from  pulpitis,  and  after  arsenical  applications  have 
been  made  to  a  pulp.     In  saturated  solution  it  has  been  used  to  reduce 
the  hypersensitivity  of  dentin.    Its  solutions  are  markedly  antiseptic  and 
are  irritant  to  soft  tissues. 

Chloroform,  Formyl  Trichlorid,  CHCI3. 

The  most  dangerous  of  the  general  angesthetics  in  dental  practice  ;  it 
should  never  be  used  in  dentistry  for  this  purpose.  The  list  of  fatalities 
recorded  from  the  employment  of  chloroform  in  tooth-extraction  is  a 
most  formidable  one.  The  semi-erect  position  adds  to  the  danger 
always  accompanying  the  use  of  this  agent.  It  is  used  in  dentistry  as  a 
counter-irritant.  A  piece  of  blotting-paper  saturated  with  chloroform 
laid  upon  mucous  membrane  or  skin,  and  its  evaporation  prevented  by 
covering  with  rubber  cloth,  acts  as  a  stimulant,  counter-irritant,  or  vesi- 
cant, according  to  the  length  of  application.  It  is  used  as  a  solvent  for 
gutta-percha  base-plate,  to  make  the  root-filling  solution  called  chloro- 
percha. 

Cobalt. 

A  powder  named  cobalt  has  been  used  to  destroy  the  vitality  of  the 
dental  pulp,  particularly  after  the  Herbst  method.  Analysis  has  shown 
this  powder  to  be  metallic  arsenic  or  arsenic  sulfid  (Kirk). 

Cocain  (Hydrochlorid),  Benzoyl-methyl  Ecgonin. 

Decomposed,  by  boiling,  into  methylic  alcohol,  benzoic  acid,  and 
ecgonin ;  therefore,  unlike  eucain,  its  solutions  cannot  be  sterilized  by 
boiling.  Solutions  of  cocain  paralyze  the  terminals  of  both  sensory  and 
special  sense-nerves  with  which  they  are  brought  in  contact.  Applied 
to  nerve-trunks  they  prevent  the  transmission  of  sensory  impressions. 
Death  from  overdose  is  due  to  paralysis  of  respiration.  Poisoning 
should  be  treated  with  stimulants — ammonia,  strychnia,  or  ether. 

It  is  used  in  dentistry  in  solutions  of  various  strengths  as  a  local 
anaesthetic.     In  from  4  to  10  per  cent,  solution  as  an  application  to  the 


556  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

mucous  membrane  to  render  incision  painless.  In  saturated  solutions 
or  in  crystals,  or  in  paste  with  glycerin,  is  used  in  acute  diseases  of  the 
pulp  as  an  analgesic.  In  solution  with  agents  added  to  overcome  ill- 
toward  effects,  and  to  prevent  the  growth  of  organisms  which  will 
develop  in  watery  solutions  of  the  drug,  cocain  is  used  as  an  agent 
foi-  hypodermatic  injection  to  render  the  operation  of  tooth-extraction 
painless. 


.  Cocain.  hydrochlorid., 

gr-i; 

Morphinse  sulph., 

gr-xV; 

Atropinse  sulph., 

gr-  lioJ 

Trinitrin  (1  per  cent,  solution), 

gtt.  j ; 

Acid,  carbolic. 

gtt.  j ; 

Aquse,  q.  s.  ft.  3ss. — M. 

The  above  is  a  full  dose,  making  about  one-half  syringeful.  The 
syringe-needle  is  passed  deep  into  the  connective  tissue  between  mucous 
membrane  and  alveolar  periosteum  over  a  root,  and  several  drops  of  the 
solution  are  injected.  A  similar  injection  is  made  upon  the  opposite 
side  of  the  same  root,  or  over  other  roots ;  extraction  should  be  done 
almost  immediately.  Prior  to  making  the  injection  the  mucous  mem- 
brane at  the  point  of  injection  should  be  carefully  sterilized,  as  should 
also  the  syringe  and  needle. 

In  strong  solution,  cocain  is  forced  into  the  dentinal  tubuli  and  into 
the  dental  pulp  by  means  of  the  cataphoric  current,  to  obtund  hyper- 
sensitive dentin  or  to  paralyze  the  pulp  and  permit  its  removal.  Cocain 
without  this  driving  force  is  ineffective  as  a  dentinal  analgesic,  even  in 
saturated  solution  or  in  glycerin  paste. 

Collodion. 

A  solution  of  pyroxylin  (gun-cotton)  in  ether  and  alcohol.  Exposed 
to  the  air,  the  solvent  evaporates  and  leaves  a  thin,  transparent,  imper- 
meable film.  Cantharidal  collodion  is  formed  by  adding  cantharides- 
extract  to  collodion.  Styptic  collodion  is  made  by  dissolving  tannic 
acid  in  collodion  :  tannic  acid,  grs.  20  ;  collodion,  ^j.  This  makes  a 
useful  application  to  oozing,  abraded  surfaces  after  previously  sterilizing 
them.     Steresol  (which  see)  varnish  is,  however,  superior  to  it. 

OoppEB,  Cuprum. 

Black  cupric  oxid  combined  with  orthophosphoric  acid  forms  a  black 
cement,  orthophosphate  of  copper,  advised  as  a  filling-cement  in  dentistry 
to  underlie  other  materials.^     Cupric  sulfate — bluestone — according  to 

^  Ames. 


COTTON— CRESOLS.  557 

the  strength  of  solution  in  which  it  is  used,  is  an  astringent  or  caustic. 
Copper  sulfate  acts  as  a  germicide,  like  the  other  metallic  salts  mentioned, 
by  causing  coagulation  of  albumin. 

Miller's '  experiments  demonstrated  that  crystals  of  eupric  sulfate 
placed  upon  the  surface  of  a  pulp  transformed  the  entire  pulp  into  a 
green,  antiseptic,  tough  mass.  It  causes,  however,  a  green  discoloration 
of  the  dentin,  and  if  used  when  putrefactive  decomposition  is  in  progress, 
black  copper  sulfid  is  formed  by  the  action  of  the  hydrogen  sulfid 
present. 

A  crystal  of  eupric  sulfate  is  a  useful  application  to  the  dentin  of 
deeply  infected  teeth  which  are  to  be  enclosed  by  barrel  crowns.  In 
strong  solution  it  is  a  useful  agent  in  the  cauterant  treatment  of  pyor- 
rhoea pockets.  In  1  per  cent,  solution  it  is  a  useful  astringent  and 
antiseptic  wash  for  relaxed   conditions   of  the  soft   tissues  about  the 

mouth. 

Cotton. 

The  hairs  of  the  seeds  of  the  cotton-plant  (gossypium  herbaceum). 
In  the  carded  state  it  is  the  raw  cotton  of  dentistry.  Boiled  with  a 
5  per  cent,  solution  of  sodium  or  potassium  hydrate,  fatty  substances 
and  foreign  matters  are  washed  away,  and  the  boiled  cotton  is  afterward 
washed  wdth  calcium  hypochlorite  ;  this  is  absorbent  cotton.  Each  fibre 
consists  of  elongated  tubular  cells,  which  absorb  any  moisture  with 
which  the  cotton  is  brought  in  contact.  The  cotton  should  contain  no 
free  alkali  or  free  acid.  Mixed  with  arsenical  paste  and  dried,  it  con- 
stitutes devitalizing  fibre. 

Corrosive  Sublimate.     (See  Mercuric  Chlorid.) 

Creosote.. 

A  product  of  the  distillation  of  wood,  etc.  ;  it  contains  carbolic  acid 
and  allied  substances  ;  its  properties  and  uses  are  those  of  carbolic  acid. 

Cresols,  nominally  CsHiCHjOH. 

methyl  phenol. 

Obtained  by  fractional  distillation  of  crude  carbolic  acid  at  365°-401° 
F.  There  are  three  cresols,  ortho-,  meta-,  and  para-cresol,  the  second 
being  the  most  ])owerful  germicide.  Para-cresol  is  a  local  analgesic, 
destroying  the  sense  of  pain,  but  not  tactile  sensibility.^  It  will  be 
seen  that  the  chemical  composition  of  these  substances  shows  them  to 
be  allied  to  cocain  and  carbolic  acid.  Frankel  and  Gruber  found 
a  mixture  of  the  three  cresols — called  trikresol — to  possess  three  times 
the  disinfectant  power  of  carbolic  acid.  Trikresol  may  be  used  with 
advantage  to  replace  carbolic  acid  in  dental  practice. 

1  Dental  Cosmos.  ^  McNeill,  Edinburgh  Med.  Jour.,  1886. 


558  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

Ergot. 
The  fluid  extract  in  drachm  doses  is  used  as  a  hsemostatic. 

Erigeron,  Fleabane. 

The  oil  of  erigeron,  in  doses  of  from  twenty  to  thirty  drops  in 
capsules,  is  used  in  oozing  alveolar  hemorrhage  after  the  extraction  of 
teeth. 

Ether,  Ethyl  Oxid,  (OJtI^).,0. 

Used  as  the  major  ansesthetic  for  dental  operations,  when  it  is  essen- 
tial to  keep  the  patient  anaesthetized  for  comparatively  long  periods,  as 
in  the  removal  of  imbedded,  impacted  teeth.  Dividing  the  anaesthetic 
stages  of  ether  into  four,  the  first  stage  is  when  sensibility  to  pain  is 
dulled  before  the  loss  of  consciousness  occurs ;  teeth  may  be  extracted 
in  this  period,  or  excessively  hypersensitive  dentin  may  be  cut,  without 
pain. 

Ethyl  Ohlorid,  C2H5CI, 

is  too  volatile  for  use  as  a  general  ansesthetic.  It  boils  at  12°  C.  It  is 
used  as  a  refrigerant  local  anaesthetic,  its  rapid  evaporation  causing 
quick  paralysis  of  sensory  nerve-terminals  or  trunks.  A  spray  of  this 
agent  directed  against  vital  dentin  will  benumb  its  sensitivity,  and  if 
the  application  be  prolonged  refrigeration  extends  to  the  pulp,  which  in 
many  cases  can  be  extracted  painlessly.  A  spray  directed  upon  the 
gum  will  freeze  it  and  permit  the  extraction  of  a  tooth  without  pain. 

EucAiN  Hydrochlorid, 

a  synthetic  substance,  having  a  methyl-benzoyl  basis,  as  in  cocain  ;  its 
composition  is,  however,  much  more  complex  than  that  of  the  latter. 
Solutions  in  water  may  be  boiled  without  decomposition  ;  hence,  unlike 
cocain,  solutions  may  be  sterilized  by  boiling.  It  is  not  so  toxic  as 
cocain.  It  may  be  used  in  watery  solutions  which  have  been  boiled,  in 
amounts  of  ^|  gr.  by  hypodermatic  injection,  to  render  tooth-extraction 
painless. 

EXALGEN,    MeTHYL-ACETANILID, 

is  acetanilid  in  which  the  remaining  hydrogen  atom  of  the  basal 
ammonia  is  replaced  by  methyl : 

/H  /CH,  (methyl) 

N— COCH3  N— COCH3 

Acetanilid  Methyl  acetanilid,  or  exalgin. 

Its  analgesic  power  is  greater  than  than  of  acetanilid.  Its  uses  are 
the  same  in  treating  painful  affections,  but  it  is  not  used  as  an  anti- 
pyretic. 


FORMALIN— HAMAMELIS.  559 

Formalin, 

a  40  per  cent,  solution  of  the  gas  formaldelyd  (CH2O)  in  water.  For- 
maldehyd  is  an  oxidation-product  of  methyl  alcohol.  A  powerful 
antiseptic ;  in  1  :  1000  solution  it  prevents  the  growth  of  anthrax 
spores  ;  in  1  :  2000  solution  it  checks  putrefaction  in  bouillon.'  The 
vapor  (powerfully  antiseptic)  is  given  off  from  formalin  solutions  at 
ordinary  temperatures.  It  produces  tough  coagula  when  brought  in 
contact  with  albuminous  substances.  Both  vapors  and  solutions  are 
very  irritating.  Any  strength  in  excess  of  5  per  cent,  placed  in  root- 
canals  is  productive  of  irritation ;  and  the  dental  pulp  responds  pain- 
fully to  any  solution  of  a  strength  above  3  per  cent."  It  is  used  in  the 
indicated  strength  in  connection  with  putrescent  pulps,  prior  to  attemj)ts 
at  mechanical  manipulation,  to  penetrate  and  sterilize  to  the  root-apex. 
In  1  per  cent,  solution  it  is  an  excellent  injection  for  deep-seated 
abscesses,  particularly  those  of  a  chronic  type.  In  1  per  cent,  solution 
in  combination  with  other  agents  it  is  an  admirable  antiseptic  mouth- 
wash. 

Glycerin,  Propenyl  Alcohol,  €3115(011)3, 

is  set  free  when  natural  fats  are  boiled  in  a  caustic  alkali.  Stearates  of 
potassium  or  sodium  (soaps)  are  formed  and  glycerin  is  liberated.  It 
has  moderate  antiseptic  powers  and  is  very  hygroscopic.  A  drachm  or 
two  injected  into  the  rectum  produce  a  watery  stool,  and  this  fact  is 
utilized  in  the  derivatant  treatment  of  teething-convulsions.  Mixed 
with  equal  parts  of  water  it  is  useful  to  relieve  "  dry  mouth  and  fauces." 
In  combination  with  tannic  acid  it  forms  glycerite  of  tannin  (which  see). 

GUAIACOL. 

A  distillation-product  of  creasote,  containing  from  60  to  90  per  cent, 
of  that  substance.  Its  uses  are  in  general  those  of  creasote.  A  10 
per  cent,  solution  of  anhydrous  cocain  hydrochlorid  in  pure  guaiacol  is 
termed  guaia-cocain,^  and  is  used  instead  of  watery  solutions  of  cocain 
in  connection  with  the  cataphoric  current  to  benumb  hypersensitive 
dentin. 

Hamamelis. 

Fluid  extract,  dose  internally  5-20  drops.  The  distilled  extract 
(Pond's  extract)  may  be  used  in  doses  of  3ss-3j  internally.  Internally 
it  is  used  as  a  haemostatic  to  check  oozing  hemorrhage.  Locally  it  is 
used  to  reduce  vascular  engorgement.  It  is  an  efficient  antiphlogistic 
for  use  in  inflammatory  conditions  of  the  mouth  and  fauces.  Is  very 
useful  as  a  general  mouth-Avash  in  cases  of  pericementitis,  after  the  excit- 

^  TJ.  S.  Marine  Hospital  Reports,  July,  1897.  ^  L.  Jack. 

3  W.  T.  Morton. 


560    •       DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

ing  causes  of  the  inflammation  have  been  removed.    It  is  used  as  a  wash 

in  cases  of  gingivitis.  a  j       *  ,        r         / 

Hydrogen  Peroxid,  Hydrogen  Dioxid,  H2O2.  g^^-^/^Uvw  (^^^y. 
In  3  per  cent,  watery  solution  yielding  ten  volumes  of  oxygen.     In  co  chr 
5  per  cent,  ethereal  solution.     In  25  per  cent,  ethereal  solution,  caustic/ 1  A^ 
pyrozone.     Sodium  dioxid,  from  which  hydrogen  dioxid  is  disengaged  ^^  i 
by  the  action  of  dilute  mineral  acids.     Most  of  the  watery  solutions  of  f^^^'t 
hydrogen  dioxid  are  slightly  acid  in  reaction.     Solutions  of  hydrogen  rw-'^ 
dioxid  deteriorate  with  age,  and  very  quickly  upon  open  exposure. 
Their  activity  may  be  judged  by  the  violence  of  the  -reaction  which 
occurs  when  potassium  permanganate  is  added  to  the  solutions.     Used 
as  a  germicide,  antiseptic,  and  disinfectant;  acting  by  virtue  of  the 
nascent  oxygen  set  free  when  the  solutions  are  brought  in  contact  with 
organic  matter.     (See  Antiseptics,  Nascent  Oxygen,  and  Caustic  Alka- 
lies.)    Used  in  abscess-cavities,  pus-pockets, 'pulpless  roots,  pulp-dis- 
eases, and  in  all  conditions  where  an  active  and  non-toxic  antiseptic  is 
indicated. 

lODIN,   lODIDS. 

Tr.  iodin  and  liq.  iodi  comp.  (LugoFs  solution).  Tr.  iodin  evapor- 
ated to  one-fourth  its  volume  is  called  dental  tincture  of  iodin.^  Iodin 
is  incompatible  with  mineral  acids,  metallic  salts,  and  vegetable  alka- 
loids. Iodin  in  vapor,  solid,  or  in  solutions,  decomposes  hydrogen 
sulphid  and  hydrogen  phosphid,  acting  as  a  deodorant.  It  combines 
with  albuminous  substances,  acting  as  a  germicide.  Locally  applied,  it  acts 
as  a  stimulant,  irritant,  or  caustic,  depending  upon  the  concentration  of 
the  solution.  It  is  used  as  a  counter-irritant  in  cases  of  pulpitis  and 
pericementitis  (acute),  and  to  resolve  indurations  about  the  teeth  due  to 
chronic  inflammation  of  the  pericementum.  Used  in  pulp-chambers 
to  quickly  deodorize  the  putrescent  pulp.  If  the  cavity  be  washed 
with  ammonia-water,  afterward  any  iodin-stain  is  removed  and  the 
dentin  whitened.  Used  diluted  in  conditions  of  tumid  gums,  and  as  a 
stimulant  application  in  deep  pyorrhoea  pockets.  The  liq.  iodi  comp.  is 
preferable  in  such  cases. 

Iodoform,  Formyl  Tri-iodid,  CHI3. 

Iodoform,  by  virtue  of  its  organic  radical,  is  a  local  ansesthetic.  It 
is  antiseptic,  although  not  a  germicide.  Its  action  in  this  direction  is 
believed  to  be  due  to  one  of  two  causes  :  either  by  virtue  of  the  iodin 
which  is  set  free  when  iodoform  is  brought  into  contact  with  infected 
tissues,  or  to  chemical  changes  which  it  induces  in  the  poisonous  prod- 

1  Flagg. 


lODOL—LYSOL.  561 

ucts  of  bacteria,  reuderiug  them  non-toxic.  The  reduction  of  irrita- 
bility by  the  formyl  radical  must,  in  addition,  play  an  important  part  in 
inducing  regeneration  of  tissues  over  surfaces  to  which  iodoform  is 
applied.  Used  in  conjunction  with  arsenic  trioxid  in  devitalizing  paste, 
it  lessens  the  pain  incidental  to  pulp-devitalization.' 

^.  Acid,  arsenosi,  gr.  v  ; 

lodoformi,  gr.  x ; 

01.  cinnamomi,  q.  s.  ft.  paste. 

There  is  much  discrepancy  of  opinion  as  to  the  value  of  iodoform, 
brought  about  by  the  observation  that  it  is  not  a  germicide  ;  nevertheless 
in  pyogenic  conditions  of  a  chronic  type  it  appears  to  have  distinct 
value.  It  is  used  in  solution  or  in  powder  in  the  cavities  of  chronic 
abscesses  or  pyorrhea  pockets.  Gauze  charged  with  iodoform,  iodoform- 
gauze,  is  used  to  pack  abscess-cavities  which  have  been  opened  artifi- 
cially through  the  alveolar  walls,  and  after  root-amputations.  Under  its 
use  regeneration  and  healing  proceed  more  uniformly  than  with  most 
medicinal  applications.  Iodoform  is  used  freely  in  cases  of  tuberculosis 
of  the  jaws. 

loDOL,  Tetra-iod-pyrrhol,  CJ4NH. 

Introduced  as  a  substitute  for  iodoform,  it  contains  about  the  same 
volume  of  iodin  in  looser  combination.  It  is  inodorous.  Applied  to 
wounds  iodin  is  set  free  and  acts  upon  albuminous  substances,  from 
which  ozone  is  disengaged,  which  oxidizes  compounds  of  sulfur  and  phos- 
phorus.^ Its  uses  are  those  of  iodoform,  except  in  arsenical  pastes, 
where  the  anaesthetic  property  of  iodoform  is  utilized. 

Iron. 

Freshlv  prepared  hvdrated  sesquioxid  of  iron  is  the  antidote  to 
arsenic.  Tr.  ferri  chlor.  is  occasionally  used  as  a  styptic  in  alveolar 
hemorrhage.  Monsell's  solution,  sol.  ferric  subsulfate,  is  a  poAverful 
styptic,  but  may  cause  sloughing  of  tissues.  Preparations  of  iron  are 
rarely  used  in  the  mouth  on  account  of  the  stains  they  produce  upon  the 
teeth. 

Kino,  Krameria, 

v^egetable  astringents  used  in  mouth-washes,  acting  by  virtue  of  the 
tannic  acid  contained  in  them. 

Lysol 

is  a  carbolized  compound,  made  by  dissolving  in  fat  and  saponifying 
with  alcohol  that  part  of  coal-tar  which  boils  between  190°  and  200°  C. 

^  Truman.  ''■  Bartholow. 

36 


562  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

It  forms  a  clear,  soapy  fluid  with  water.  Is  used  in  2  to  4  per  cent, 
solution  to  sterilize  the  washed  hands,  and  in  boiling  solutions  of  the 
same  strength  to  sterilize  instruments.  In  full  strength  it  is  an  excel- 
lent penetrating  antiseptic  as  a  first  application  to  pulps  in  a  state  of 

partial  putrescence. 

Magnesium. 

Magnesium  hydrate  in  suspension  is  Phillip's  milk  of  magnesia. 
It  is 'perhaps  the  best  of  all  antacids  for  use  in  dental  therapeusis. 
It  forms  a  film  of  magnesium  hydrate  upon  the  surfaces  of  the  teeth 
and  aids  materially  in  checking  the  advance  of  dental  erosion. 

Magnesium  sulfate  in  doses  of  Bss,  well  diluted,  is  an  excellent 
derivative  saline  cathartic  in  cases  of  acute  pericementitis. 

Menthol,  Mint  Camphor. 

The  active  principle  of  peppermit,  upon  which  its  effects  depend.  It 
is  a  local  ansesthetic  and  produces  contraction  of  the  small  vessels  of  the 
part  to  which  it  is  applied.  This  combination  of  properties  renders  it 
very  useful  in  treatment  of  acute  pulpitis.  Used  dissolved  in  chloroform 
or  oil  of  cassia,  it  is  an  excellent  agent  in  the  treatment  of  the  peri- 
cemental irritation  which  occasionally  follows  upon  the  removal  of  the 
pulp.  It  is  pumped  in  the  canals  and  permitted  to  remain  for  a  day  or 
longer.  A  solution  (gr.  j-5)  is  a  useful  wash  in  cases  of  sluggish 
stomatitis. 

Mercury. 

Metallic  mercury  is  used  as  the  solvent  of  dental  alloys. 

Mercury  bichlorid,  HgClg,  in  strength  of  1  :  2000  ^  is  found  to  act 
as  an  effective  sterilizing  agent  in  the  human  mouth,  killing  in  a  very 
few  minutes,  nearly  all  forms  of  bacteria  found  in  that  cavity.  Its 
disagreeable  taste  and  the  danger  of  discoloring  the  dentin  of  the  teeth 
contraindicate  its  use  as  a  general  oral  antiseptic.  In  pulpless  teeth, 
particularly  in  those  in  which  the  pulp  has  become  gangrenous  and  un- 
dergone putrefactive  decomposition,  the  use  of  mercuric  chlorid  is  con- 
traindicated  because  of  its  reaction  with  the  hydrogen  sulfid  generated 
during  this  type  of  fermentation.  The  danger  of  discoloring,  salts 
of  mercury  being  formed  and  finding  their  way  into  the  dentinal  tubuli, 
is  an  ever-present  one.^ 

It  has  been  found  that  tablets  composed  of  mercury  bichlorid  and  thy- 
mol in  equal  parts,  when  crushed  in  the  base  of  a  pulp-chamber  against 
the  stumps  of  pulps  which  have  been  intentionally  devitalized,  will  main- 
tain a  prolonged  antiseptic  condition  in  the  roots  of  teeth  so  treated.^ 

^  Miller,  Micro-organisms  of  the  Human  Month. 
''■  Kirk's  Operative  Dentistry,  chapter  "Bleaching." 
^  Miller,  Proc.  Columbia  Dental  Congress. 


METHYL  CHLORID— MORPHIA.  563 

Corrosive  sublimate  has  found  but  limited  clinical  application  in  dental 
practice,  it  being  possible  to  induce  antisepsis  Mith  other  germicides 
which  have  not  the  disadvantageous  features  of  the  mercury  salt.  It  is 
not  adapted  for  sterilizing  metallic  instruments  on  account  of  its  corro- 
sive action  upon  steel,  and  the  precipitation  of  mercury  upon  other 
metals.  In  hot  1  :  2000  solution  it  is  an  effective  sterilizer  for  glass- 
ware used  by  the  dentist.  In  1  :  1000  solution  it  is  an  effective  lavage 
in  conditions  of  ulcerous  stomatitis,  although  hydrogen  dioxid  followed 
by  potassic  chlorate  has  largely  displaced  it  for  this  purpose.  A  1  :  1000 
solution  in  hydrogen  dioxid  is  an  excellent  germicidal  application  to 
abscess-walls.' 

Mercury  sulfid,  HgS,  vermilion,  is  the  pink  coloring-matter  of 
gutta-percha  base-plate.  As  this  salt  is  insoluble  in  lactic  acid,  fillings 
made  of  pink  gutta-percha  do  not  acquire  a  rough  surface  like  those 
made  of  preparations  containing  the  soluble  zinc  oxid.  The  red  oxid 
of  mercury  is  used  as  an  ingredient  for  lip-salves  to  relieve  cracks  and 
abrasions  about  the  lips  : 

^.  Mercuric  oxid.,  3j  ; 

Tr.  benzoin,  3j  ; 

Cerat.  simp.,  gij  ; 

Liq.  potassii,  gtt.  ij, — M.  et  ft.  ungent. 

(J.  F.  Flagg). 

Methyl  Chlorid,  Mono-chlor-methane,  CH3CI, 

the  lightest  and  most  volatile  of  the  compounds  of  chlorin  with  methane, 
the  heaviest  being  chloroform,  tri-chlor-methane,  CHCI3.  Methyl 
chlorid  vaporizes  at  a  temperature  below  zero ;  hence  it  is  the  most 
active  refrigerant  available  as  a  local  anaesthetic.  It  possesses  an  addi- 
tional advantage  over  ethyl  chlorid,  in  that  it  is  but  slightly  inflam- 
mable. A  spray  of  methyl  chlorid  directed  against  the  gum  for  a  frac- 
tion of  a  minute  or  longer  will  create  sufficient  local  anaesthesia  to 
render  the  operation  of  tooth-extraction  painless.  The  application 
should  not  be  continued  too  long,  or  tissue-death  will  result.  A  spray 
directed  against  hypersensitive  dentin  or  an  exposed  pulp,  will  render 
both  entirely  anaesthetic.  Vital  pulps  may  be  rapidly  paralyzed  through 
the  application  of  a  spray  of  methyl  chlorid.  The  spray  may  be  used 
as  a  cold  test  to  determine  the  vitality  of  a  pulp.^ 

Morphia. 

The  anodyne  alkaloid  of  opium.  It  possesses  the  power  of  benumb- 
ing the  functions  of  the  sensory  nervous  tract  when  internally  admin- 

iRhein.  ^Ihid. 


564  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

istered.  Locally  applied  it  is  an  obtundent  to  sensory  nerve-terminals. 
The  sulfate  is  the  most  effective  salt  for  internal  use  ;  the  acetate  for 
external  ajsplication.  Morphinse  sulfate,  gr.  ^,  administered  a  half-hour 
before  operating  will  in  many  cases  so  benumb  sensitivity  that  the  pain 
of  cutting  hypersensitive  dentin  is  materially  reduced.  The  same 
dose  may  be  required  as  a  general  anodyne  in  conditions  of  pulpitis  and 
acute  pericementitis ;  it  has  been  largely  displaced  for  such  purposes 
by  the  coal-tar  derivatives,  which  relieve  pain  without  the  unpleasant 
after-effects  frequently  following  upon  the  use  of  morphia — i.  e.,  con- 
stipation and  headache. 

Acetate  of  morphia  was  the  usual  anodyne  ingredient  in  arsenical 
paste-formulae ;  it  has  been  almost  entirely  superseded  by  cocaiu  hydro- 

chlorid. 

Naphthalin,  CioHg. 

The  naphthalin  derivatives  are  all  analogues  of  carbolic  acid.  Resor- 
cin  (which  see)  belongs  also  in  this  chemical  and  medicinal  group.  Car- 
bolic acid  and  resorcin  belong  in  the  group  which  has  but  a  single  ben- 
zene nucleus,  CgHg :  naphthalin  in  that  having  a  double  benzene  nucleus. 
Phenylic  alcohol  is  benzene  in  which  one  hydrogen  atom  is  replaced  by 
hydroxyl,  CgHgHO.  Resorcin  has  two  of  its  hydrogen  atoms  so  re- 
placed, CgH/HO),. 

Naphtol. 

The  hydroxyl  derivative  of  naphthalin  has  the  composition  Cj^H-HO. 
There  are  two  naphtols,  the  alpha  and  the  beta,  both  having  the  same 
formula — are  isomeric.  The  latter  is  more  soluble  in  hot  water,  and  its 
leaflet-like  crystals  have  lower  melting-  and  boiling-points  than  the 
needle-like  crystals  of  a-naphtol.     Only  y3-naphtol  is  used  in  surgery. 

Hydronaphtol,  a  proprietary  agent,  is  said  to  be  identical  with  ;5- 
naphtol.^  The  penetrating  and  preserving  qualities  of  this  agent,  how- 
ever, appear  to  be  superior  to  those  of  /9-uaphtol. 

Naphtol  solutions  are  made  in  alcohol,  these  solutions  being  mis- 
cible  in  hot  water.  Miller's  experiments  indicate  that  these  solutions 
are  promptly  germicidal,^  but  that  they  do  not  induce  prolonged  anti- 
sepsis.^ 

The  chemical  analogy  of  naphtol  to  carbolic  acid  is,  of  course,  an 
indication  of  some  or  of  a  close  degree  of  physiological  properties. 

/9-naphtol  or  hydronaphtol  in  1  :  300  solution  is  used  as  a  spray 
for  sterilizing  pyorrhoea  pockets,  for  sterilizing  alveoli  after  extraction 
and  prior  to  plantation  operations.  In  1  :  50  solution  or  stronger  it  is 
used  in  septic  pulp-canals,  and  in  the  treatment  of  septic  apical  peri- 
cementitis. 

^  Gould,  Illustrated  Did.  of  Medicine.         ^  Micro-organimis  of  the  Human  Mouth. 
3  Denial  Cosmos,  1891. 


NITROUS  OXIl)— OXYGEN.  565 

Nitrous  Oxid,  Nitrogen  Monoxid,  N,0. 

The  only  entirely  safe  general  anfesthetic.  Anaesthesia  is  induced  in 
from  one-half  to  two  minutes,  and  ceases  in  from  one  to  three  minutes. 
Ill-effects  from  its  use  are  rare ;  those  that  have  been  noted  were  usu- 
ally in  patients  whose  vessels  were  atheroma,tous.  Patients  having  ])ul- 
monary  emphysema,  or  fatty  heart,  may  be  distressed  for  hours  after  its 
administration,  and  its  use  in  the  three  classes  of  disorders  named  can- 
not be  regarded  as  without  danger. 

Oils,  Antiseptic. 

Several  of  the  essential  volatile  oils  are  used  in  dental  practice  as 
antiseptics.  In  addition,  most  of  them  possess  obtundent  action  upon 
the  dental  pulp.  The  several  oils  differ  as  to  their  activity  in  both  of 
these  directions.  All  of  these  oils  belong  to  the  aromatic  series — i.  e., 
they  have  a  relationship  to  benzene. 

The  oil  of  caryophyllum  (cloves)  contains  an  oxygenated  oil.  Eu- 
genol,  having  basic  properties,  is  eugenic  acid.  The  oils  of  cajuput, 
cassia,  and  cinnamon  (cassia  being  the  Chinese  cinnamon,  the  Ceylon 
oil  that  of  cinnamon  proper),  eucalyptus,  gaultheria,  myrtle,  and  thyme, 
all  find  useful  application  in  dentistry.  Of  these,  oil  of  wintergreen 
possesses  the  least  antiseptic  properties,  oil  of  eucalyptus  the  least  ob- 
tundent action ;  the  most  powerful  antiseptic  action  being  in  the  oils  of 
myrtle,  cinnamon,  and  thyme,  the  last  named  being  the  most  marked 
antiseptic  and  obtundent.  It  owes  its  efficiency  to  a  stearopten,  thymol 
(which  see),  contained  in  it.  These  oils  may  be  applied  freely  to  exposed 
and  aching  pulps,  benumbing  them  quite  promptly  and  apparently  hav- 
ing no  deleterious  action  upon  their  vitality. 

Oil  of  cinnamon  is  a  persistent,  and  powerful,  slowly  diffusing  anti- 
septic. It  appears  to  preserve  stumps  of  pulps  with  which  it  is  placed 
in  contact.  This  oil  has  wide  application  in  the  treatment  of  septic  pulp- 
canals  and  their  chronic  sequelae. 

Oxygen. 

Oxygen  in  gaseous  form  is  combined  with  nitrous  oxid  (method  of 
Hewitt)  to  reduce  or  prevent  the  occurrence  of  the  lividity  due  to  a  de- 
privation of  oxygen,  when  nitrous  oxid  is  administered  alone.  Nascent 
oxygen  is  disengaged  from  compounds  in  which  it  is  loosely  combined, 
as  the  dioxids  of  hydrogen  and  sodium  (see  Hydrogen  Dioxid),  to  act 
as  a  germicide,  disinfectant,  and  bleaching-agent.  Liberated  from  these 
compounds  in  contact  with  decomposing  organic  matter,  the  nascent 
oxygen  seizes  upon  the  hydrogen  of  such  substances,  effecting  their 
decomposition.     Nascent  oxygen  quickly  destroys  the  vitality  of  bac- 


566  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

teria.     Uniting  with  the  hydrogen  of  staining  substances,  it  effects  a 
bleaching  by  their  decomposition. 

Paraffin. 

Specimens  of  hard  paraffin,  those  having  high  melting-points,  are 
used  either  alone  or  combined  with  other  substances,  as  iodoform  or 
aristol,  as  canal-fillings. 

Phenacbtin,  C10H13NO,  or  C6H,(C,H50)NH,C,H30. 

Acetphenetidin  or  phenylacetin  is  a  tasteless  coal-tar  derivative  having 
greater  antipyretic  and  analgesic  powers  than  acetanilid.  Dose,  iij-x 
grains. 

Plumbum,  Lead. 

The  acetate,  in  the  form  of  liq.  plumbi  subacetatis,  is  the  basis  of 
lead-water.  It  is  an  astringent  antiphlogistic,  producing  contraction 
of  bloodvessels  of  parts  to  which  it  is  applied.  It  is  a  useful  sedative 
antiphlogistic  in  cases  where  the  inflammation  from  alveolar  abscess 
has  invaded  the  tissues  of  the  cheek.  It  is  applied  externally.  Inter- 
nally this  solution  is  actively  poisonous. 

The  following  is  the  well-known  lead-water  and  laudanum  mixture  : 

^.  Liq.  plumbi  subacet.,  .liv  ; 

Tr.  opii,  Sj  ; 

Aquse,  Oj. — M. 

Sig.  Applied  on  compresses  to  the  inflamed  parts. 

Potassium. 

Several  potassium  salts,  and  also  the  metal  itself,  are  employed  in 
dental  therapy.  The  metal  is  used  in  alloy  with  metallic  sodium  to 
effect  the  quick  decomposition  of  the  products  of  putrefaction  in  pulp- 
canals.  It  seizes  upon  the  hydroxy]  elements  of  these  substances, 
forming  potassium  and  sodium  hydroxids,  which  in  their  turn  act  upon 
the  canal-contents,  converting  them  into  innocuous  and  soluble  sub- 
stances. Applications  of  potassium  sodium  (kalium-natrium)  should 
precede  all  attempts  at  tooth -bleaching,  as  the  bulk  of  the  offending 
material  is  thus  removed,  permitting  the  passage  of  nascent  oxygen  or 
chlorin  to  the  deeper  parts  of  the  discolored  dentin.^ 

Potassium  bromid  in  doses  of  three  grains  is  a  useful  remedy  to 
lessen  the  reflex  cerebro-spinal  irritation  of  children  due  to  teething. 
In  cases  of  convulsion  it  is  administered  by  the  rectum  in  combination 
with  chloral  hydrate,  suspended  in  starch  mixture.     A  full  dose,  grs. 

1  Kirk. 


PYROZONE— SACCHARIN.  567 

xx-xxx,  will  in  many  cases  relieve  the  wakefulness  accompanying  pain- 
ful dental  affections. 

Potassium  carbonate  in  saturated  solution  in  glycerin  is  a  powerful 
obtundent  of  hypersensitive  dentin.  It  is  also  antiseptic,  destroying 
the  putrid  contents  of  pulp-chambers. 

Potassium  chlorate  in  strong  solutions  is  an  effective  agent  in  all 
forms  of  stomatitis.     It  is  particularly  valuable  in  mercurial  stomatitis. 

Potassium  hydrate,  as  a  germicide  and  disinfectant,  has  been  de- 
scribed above. 

A  mixture  of  potassium  hydrate  and  carbolic  acid  equal  parts,  lique- 
fied with  alcohol,  is  a  powerful  obtundent  of  hypersensitive  dentin.  It 
is  an  irritant  caustic  (Robinson's  Remedy). 

Potassium  iodid  in  ointment  is  a  useful  application  to  indurations 
about  the  jaws,  left  as  the  result  of  chronic  inflammations. 

^.  Potassii  iodid.,  gr.  xx  ; 

Cerat.  simp.,  5j. — M.  et  ft,  unguent. 

Potassium  iodid  is  administered  internally  in  cases  of  mercurial 
stomatitis,  pericementitis,  and  periostitis,  as  an  eliminative  agent. 

Potassium  permanganate  is  an  effective  oxidizing  deodorant  and 
antiseptic  ;  its  germicidal  power  is  very  doubtful.  In  contact  with 
organic  matter  it  gives  up  its  oxygen  and  is  reduced  to  manganese  oxid. 
It  is  a  chemical  antidote  of  morphin,  and  of  snake-venom.^  It  is  used 
in  claret-colored  solutions  to  deodorize  an  offensive  mouth. 

Pyrozone.     (See  Hydrogen  Dioxid.) 

QUERCUS. 

A  tincture  of  quercus  alba,  or  white-oak  bark,  diluted,  is  used  as  an 
astringent  to  reduce  the  tumidity  of  the  gums. 

QuiLLAiA,  Soap-bark, 
is  used  powdered,  as  a  substitute  for  powdered  Castile  soap  in  dentifrices. 

•Resorcin,  C6H4(H0)2. 

A  close  analogue  of  carbolic  acid,  C^H-HO.  Is  more  poisonous  than 
carbolic  acid,  and  does  not  act  so  promptly."^  Its  uses  are  similar  to 
those  of  carbolic  acid.     It  is  more  soluble  in  water  than  the  latter. 

Saccharin,  C6H4rCO)rSO,)NH,  Benzoyl-sulphonic  Imide. 
A  coal-tar  derivative  more  than   two  hundred  times  sweeter   than 

^  S.  Weir  Mitchell.  -  Brunton. 


568  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

sugar;  it  is  antiseptic,  checking  fermentations.  For  this  reason  a 
minute  portion  is  used  as  the  sweetening  agent  in  mouth-washes,  instead 
of  sugar.     The  solution  must  be  made  with  alcohol. 

Salol,  Phenyl  Salicylate,  C6H,(0H)(C0.0C6H5). 

A  white  crystalline  powder  insoluble  in  water,  melting  at  about 
105°  F. ;  it  remains  fluid  for  some  time  after  reduction  to  a  tempera- 
ture below  that  of  the  body.  It  is  decomposed  by  alkalies  into  carbolic 
and  salicylic  acids.  It  has  been  used  in  its  melted  state  as  a  root-canal 
filling.  Administered  internally  in  5  gr.  doses  to  relieve  rheumatic 
pains  about  the  jaws. 

Silver. 

Silver  nitrate  (argenti  nitras)  is  employed  in  all  strengths  from  a  1 
per  cent,  solution  to  the  fused  nitrate — the  solid  stick  or  lunar  caustic. 
Nitrate  of  silver  exposed  to  sunlight  undergoes  decomposition  and  is 
reduced  to  the  oxid.  Brought  in  contact  with  albuminous  substances, 
silver  nitrate  combines  with  them,  forming  the  albuminate  of  silver.  It 
has  been  held  by  writers  upon  pharmacology  that  the  action  of  silver 
nitrate  applied  to  a  surface  was  very  superficial ;  that  a  film  of  silver 
albuminate  formed  and  the  chemical  reaction  ceased.  Experiments  by 
Truman  ^  have  shown  that  its  penetrative  power  is  very  great  as  com- 
pared with  other  coagulants.  Placed  at  one  end  of  a  capillary  tube 
containing  a  solution  of  albumin,  silver  nitrate  quickly  brings  about 
coagulation  to  the  extremity  of  the  tube. 

It  has  long  been  used  as  an  empirical  remedy  for  traumatic  erysip- 
elas, for  which  it  has  been  held  to  be  a  specific.  To  act  as  a  germicide  in 
such  cases  its  action  must  be  penetrating,  as  the  streptococci  of  erysipelas 
are  deeply  situated. 

Nitrate  of  silver,  in  saturated  solution,  is  used  to  arrest  caries  in 
deciduous  teeth  (see  Chapter  XXVII.)  and  also  to  destroy  hyper- 
sensitivity of  dentin ;  its  deeply  penetrative  action  suggests  caution  in 
this  direction.  It  is  never  used  except  in  posterior  teeth  because  of  its 
staining,  owing  to  the  reduction  of  the  silver  albuminate  to  silver  oxid. 

In  5—10  per  cent,  solution  it  is  used  as  a  wash  for  pyorrhoea  pockets 
in  which  pus-formation  and  congestion  are  persistent. 

Other  salts  of  silver,  notably  the  citrate  and  lactate,  have  been 
shown  to  be  prompt  and  effective  germicides.  The  silver  citrate  is 
soluble  in  the  proportion  of  about  1  :  3800  in  water,  in  which  strength 
it  is  sufficiently  active  to  sterilize  the  cavities  of  abscesses  and  as  a  wash 
in  inflammatory  and  suppurative  affections  about  the  jaws.  The  stains 
upon  the  enamel  are  easily  removable  by  means  of  common  abrasives. 

^  Proc.  Academy  of  Stomatology,  1895. 


SODIUM.  569 

The  powdered  silver  citrate  should  make  a  valuable  addition  to  the 
melted  paraffin  for  use  as  a  canal-filling  in  posterior  teeth. 

The  lactate  of  silver,  soluble  1  :  15  in  water,  is  slightly  irritating. 

Sodium, 

The  sodium  salts  are  usually  regarded  as  having  therapeutic  pro])er- 
ties  similar  to  those  of  the  potassium  salts.  Bartholow '  maintains  strongly 
that  they  differ  in  essential  properties ;  the  sodium  salts  are  more  dif- 
fusible, are  less  irritating  to  mucous  membranes,  and  are  less  toxic  to  the 
tissues,  including  the  cerebral  and  circulatory  centres.  Potassium  salts 
are  more  active  in  promoting  destructive  metamorphosis,  and  in  removing 
inflammatory  growths  and  promoting  excretion.  "What  has  been  said 
of  the  dental  uses  of  potassium  bromid,  carbonate,  and  hydrate,  and 
metallic  potassium,  applies,  however,  to  the  corresponding  salts  of 
sodium. 

Sodium  biborate,  borax,  Na2B^07  +  lOHjO,  is  used  in  solution  with 
glycerin  in  the  treatment  of  catarrhal  and  ulcerative  stomatitis  of 
children. 

Sodium  bicarbonate,  NaHCOg,  is  used  in  carious  cavities  to  lessen 
dentinal  hypersensitivity  by  neutralizing  the  acids  to  which  the  condition 
is  probably  due.^ 

Sodium  phenate,  phenol  sodique,  CgHjNaO,  is  used  as  an  antiseptic 
and  styptic.  It  is  a  local  ansesthetic  ;  its  common  uses  are  those  of 
carbolic  acid,  but  it  is  without  the  cauterant  action  of  the  latter. 

Sodium  peroxid,  Na202,  in  contact  with  organic  matter  sets  free 
nascent  oxygen ;  the  sodium  oxid  left  is  quickly  converted  into  sodium 
hydrate,  having  the  properties  of  that  substance.  Solutions  must  be 
made  gradually  and  in  ice-cold  distilled  water,  as  the  heat  of  combina- 
tion raises  the  temperature  of  the  water,  and  oxygen  escapes.  A 
saturated  solution  is  first  made,  which  is  afterward  diluted  with  dis- 
tilled water.  Powdered  sodium  dioxid  is  hygroscopic  and  is  rapidly 
decomposed  upon  exposure  to  the  air.  In  saturated  solution  (applied  by 
means  of  aluminum,  gold,  or  platinum  points)  it  is  used  in  the  treat- 
ment of  putrescent  pulps,  and  as  a  bleaching  agent  for  discolored  den- 
tin. It  possesses  the  properties  of  sodium  hydroxid  and  nascent 
oxygen. 

Sodium  sulfite,  '^?i.^0^  +  THjO.  A  mixture  of  sodium  sulfite, 
10  parts,  and  boric  acid,  7  parts,  made  dry,  is  inserted  into  the  cavity  of 
a  tooth  in  which  the  dentin  is  to  be  bleached;  when  water  is  applied 
a  reaction  occurs,  sulfurous  acid  being  liberated  : 

2H3BO3  +  3Na2S03=-  2Na3B03  +  3H,0  +  3SO2.' 

^  International  Clinics,  1898,  vol.  iv.,  7th  series.  ^  Truman, 

^  Kirk,  American  Text-book  of  Operative  Dentistry. 


570  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

Unlike  sodium  dioxid  and  chlorin,  this  substance  SO2,  bleaches  by 
reduction,  abstracting  the  oxygen  from  the  pigment-molecule. 

Sodium  silico-jluorid  (salufer),  NagSiFg.  Sodium  silicate,  liquid 
silex,  ^338103.  The  latter  substance  has  antiseptic  properties.  In 
the  former  the  antiseptic  and  deodorant  properties  are  marked.  Sodium 
silico-fluorid  is  soluble  in  about  the  proportion  of  1  per  cent,  in  water. 
In  this  strength  it  has  been  used  in  the  treatment  of  putrescent  pulps. 

SozoiODOL,  C6H,(HS03)l20H, 

is  a  compound  of  iodin  with  paraphenol  sulphonic  acid.  It  is  used  as 
an  antiseptic  in  pyorrhoea  pockets.  Miller's  experiments^  show  that 
sozoiodol  salts  are  but  weak  dental  antiseptics. 

Thymol, 

a  stearoptene  derived  from  the  volatile  oil  of  thyme,  is  methy-propyl- 
phenol,  C6H3(CH3)(C3ll7)HO.  It  is  soluble  in  alcohol  and  ether.  It 
possesses  the  properties  of  a  methyl  phenyl — i.  e.,  is  markedly  antiseptic 
and  analgesic.  It  is  extensively  used  as  an  analgesic  and  antiseptic  in 
the  treatment  of  diseases  of  the  pulp. 

Trichlorphenol,  CgHaClsHO, 

is  a  powerful  and  penetrating  antiseptic,  stronger  than  carbolic  acid. 
"  It  possesses  the  power  of  penetrating  pulp-tissue  rapidly,  thoroughly 
hardening  it  and  imparting  to  it  a  pink  to  red  color.  Its  pulp-preserv- 
ing power  is  very  high."  ^  It  is  applied  to  pulps  which  have  been  but 
partially  devitalized  by  arsenic,  to  sterilize  them  and  complete  their 
devitalization. 

Dental  Varnishes. 


I^.  Gum  sandarac, 

^ij; 

Alcohol, 

Oj. 

Mix,  and  aid  solution  with  heat. 

Filter  solution  through  cotton- 

wool. 

This  is  used  in  the  dental  laboratory  as  a  separating  medium  and  to 
varnish  casts. 

Pellets  of  cotton-wool  dipped  in  the  sandarac  solution  are  used  to 
cover  medicinal  applications  in  teeth  and  to  prevent  the  ingress  of 
foreign  materials.  Being  in  no  degree  antiseptic,  and  becoming  foul 
after  twenty-four  hours  or  longer,  soft  gutta-percha  preparations 
(temporary  stopping)   have   largely  superseded   cotton   and   sandarac. 

^  Denial  Cosmos,  1890.  ^  Miller,  Dental  Cosmos,  1895. 


DENTAL   VARNISHES.  571 

Renewed  every  day,  cotton  and  sandarac  dressings  are  useful  to  press 
away  the  gum  overlianging  the  margins  of  cavities,  to  check  alveolar 
hemorrhage,  and  to  tempoi'arily  close  the  crowns  of  teeth  under  treat- 
ment. It  is  also  used  to  varnish  the  walls  of  prepared  cavities  prior  to 
inserting  plastic  fillings,  to  prevent  the  irritation  incident  to  the  applica- 
tion of  zinc  oxychlorid  cement,  and  to  prevent  the  irritation  of  zinc  phos- 
phate in  a  soft  state,  due  to  its  acid  reaction  in  this  condition  ;  and  also 
to  prevent  the  action  of  the  acid  upon  dentinal  walls.  It  is  also  used 
to  prevent  the  action  of  acid  substances  which  may  be  present  as 
impurities  in  zinc-cement  fluids,  notably,  the  acid  sodium  phosphate, 
dihydrogen  sodium  phosphate  (HjNaPO^). 

SHELLAC   VARNISH. 

The  coloring,  separating  medium  of  the  dental  laboratory. 

I^.  Gum  shellac,  3ij  ; 

Alcohol,  Oj.— M. 

Aid  solution  by  heat. 

In  its  unmodified  form  it  has  but  little  use  aside  from  that  of  the 
first  or  coloring  varnish  applied  to  plaster  impressions.  It  is  used  to 
apply  to  enamel-surfaces  which  have  been  cleansed  with  chloroform,  to 
secure -greater  adhesion  between  orthodontic  rings  and  the  teeth.  The 
tooth  to  which  a  "  regulating  ring "  is  to  be  applied  is  washed  with 
chloroform,  dried,  and  a  coating  of  shellac  varnish  given  to  the  part 
to  be  covered  by  the  ring.  The  latter  is  painted  with  zinc-phosphate 
cement,  which  is  also  applied  over  the  shellac  coating,  and  the  ring 
pressed  into  place  ;  the  parts  should  be  kept  dry  until  the  cement  is 
hard.  Combined  with  appropriate  antiseptics  shellac  varnish  makes 
an  admirable  protective  covering  to  abraded  surfaces  of  the  mouth 
which  might  invite  infection. 

The  following  formula  (steresol)  has  been  given  by  M.  Berlioz,^  of  Gren- 
oble, France,  for  an  adhesive,  anaesthetic,  antiseptic,  impermeable  coating 
to  be  applied  over  abrasions,  wounds,  etc.,  of  the  tissues  of  the  mouth. 


^. 

Purified  gum  lac. 

270  gms.,  about 

5  ix; 

Purified  gum  benzoin, 

10     "" 

3  3^; 

Balsam  of  tolu. 

10     "          " 

si; 

Oil  of  cinnamon  (Chinese), 

6     " 

Acid,  carbolic. 

100    " 

3iij; 

Saccharin, 

6     " 

Zl    . 

•35  f 

Alcohol,                             q.  s. 

ft.  one  liter,     " 

Oij. 

^  Dental  Cosmos 

K  1895. 

572  DENTAL  PHARMACOLOGY  AND  MATERIA  MEDICA. 

Veratrum  Viride. 

Its  tincture,  in  from  2  to  4  drop  doses,  is  used  to  reduce  the  force 
of  the  circulation  in  the  early  stages  of  sthenic  inflammations ;  it  is  to 
be  preferred  to  aconite  in  this  connection,  because  it  causes  vomiting 
before  a  lethal  dose  has  accumulated  in  the  system.^ 

Veratrina. 

The  paralyzant  alkaloids  of  veratrina  sabadilla,  not  of  veratrum 
viride.  There  are  at  least  three  alkaloids  entering  into  the  compo- 
sition of  commercial  veratrina  (U.  S.  Dispensatory).  The  U.  S.  P. 
(p.  204)  ointment  is  used  to  rub  over  the  temporo-maxillary  articula- 
tion and  over  the  masseter  muscle  to  relieve  spasm  due  to  difficult 
eruption  of  the  lower  third  molar.  It  should  be  used  in  small  amount 
and  be  kept  away  from  the  mouth  and  eyes,  as  it  is  actively  poisonous. 

Zinc. 

Zinc  derivatives  are  among  the  most  important  therapeutic  agents 
of  dentistry. 

Zinc  chlorid,  ZnClg,  is  very  deliquescent;  it  abstracts  moisture 
from  the  atmosphere  and  becomes  fluid  soon  after  exposure.  It  com- 
bines readily  and  actively  with  albuminous  substances,  forming  zinc 
albuminate.  Applied  to  living  tissues,  the  combination  occurs  promptly 
and  is  attended  with  much  pain. 

Truman  found  ^  that  its  penetrative  pow*er  in  saturated  solution  was 
greater  than  that  of  any  other  coagulant.  In  from  10  to  20  per  cent, 
solution  it  is  a  powerful  astringent.  The  degree  of  astringency  may  be 
graded  by  varying  the  percentage-strength  of  the  solution.  In  1  to  5 
per  cent,  solution  this  substance  is  a  stimulant,  astringent,  and  germi- 
cide. It  is  used  in  full  strength  to  obtund  the  hypersensitivity  of 
peripheral  dentin.  In  saturated  solution  it  is  the  fluid  of  zinc-oxy- 
chlorid  cement: 

ZnO  +  ZnCl^  +H2O  =:  2ZnClHO. 

A  paste  which  hardens  and  maintains  an  antiseptic  action  for  some 
time  after  hardening.  Zinc  chlorid,  in  50  per  cent,  solution,  or  stronger, 
is  used  to  coagulate  the  contents  of  the  dentinal  tubuli  after  devitaliza- 
tion and  removal  of  the  dental  pulp.  As  a  germicide,  astringent,  and 
stimulant,  it  is  a  useful  agent  in  tlie  treatment  of  pyorrhoea  alveolaris ; 
also  in  cases  of  chronic  abscess  with  serous  exudations. 

Zinc  iodid,  in  20  per  cent,  solution,  is  an  excellent  application  to 
pyorrhoea   pockets   in   cases   of    phagedenic    pericementitis,    after   the 
^  Hare.  *  Proc.  Academy  of  Stomatology,  1895. 


ZINC.  573 

removal  of  calculi  and  the  washing  of  the  pockets  (Harlan).  It  is  an 
excellent  stimulant  wash  for  the  same,  in  2  per  cent,  solution  for  subse- 
quent applications. 

Zinc  oxid  is  the  basal  powder  of  the  zinc  cements,  the  oxychlorid, 
the  phosphate,  and  zinc  oxysulfate.  It  may  contain  arsenic  trioxid  as 
an  impurity,  in  which  event  cements  made  of  it  may  kill  the  dental 
pulp.     An  ointment  of  zinc  oxid  is  used  upon  abrasiojis  about  the  lips. 

The  orthophosphate  of  zinc,  a  combination  of  orthophosphoric  acid 
with  zinc  oxid,  is  the  most  important  of  dental  cements  : 

3ZnO  +  2H3PO,  =  ZnlVO^\  +  3H,0. 

Zinc  sulfate  in  saturated  solution,  if  combined  with  a  powder  of  zinc 
oxid,  forms  an  oxysulfate  of  zinc,  a  body  having  about  the  hardness  and 
porosity  of  plaster  of  Paris ;  this  compound  is  used  to  protect  fully  or 
partially  exposed  pulps.  Zinc  sulfate  in  10  per  cent,  solution  is  a  useful 
astringent  wash  in  stomatitis. 

Black's  1-2-3  Mixture. 

Oil  of  cinnamon,  1  part ; 

Carbolic  acid,  2  parts  ; 

Oil  of  gaultheria,  3  parts. 


IXDEX. 


ABNORMAL   food-supply   as   a   disease- 
cause.  33 
Abnormalities  of  teeth,  206 
Abrasion  of  dentin,  2(31 

of  teeth,  245 
Abscess,  acute  alveolo-dental,  394 
causes  of,  394 
clinical  history  of,  398 
diagnosis  of,  401 
discharge  of,  395  '^*'" 
extension  of,  398 
pathology  of,  395 
pneuiuococcus  in,  395 
prognosis  of,  401 
pypemia  in,  402 
septicseniia  in,  402 
stages  of.  398 
sterilization  in,  402 
symptoms  of.  397 
tissue-destruction  in,  395 
treatment  of  4U2 
chronic  alveolo-dental,  407 
anatomy  of,  411 
diagnosis  of,  413 
pathology  of,  407 
symptoms  of,  413 
treatment  of,  415 
chronic  alveolar,  aspiration  of,  411 

without  fistula,  treatment  of.  409 
upon  deciduous  teeth,  treatment  of.  498 
dental,  amputation  of  root-apex,  416 
in  cachectic  persons,  401 
chronic,  burrowing  of  pus  in,  408 
diagnosis  of,  408 
with  fistula,  411 
opening  beneath  chin,  412 
into  dental  canal,  413 
on  fiice,  412 
into  nose,  414 
prognosis  of,  409 
symptoms  of,  408 
treatment  of,  409 
opening  in  antrum,  400 
externally,  405 
in  neck,  405 
in  nose,  399 
stripping  of  periosteum  in,  399 
treatment  of,  by  electrolysis,  415 
by  poultices,  401 
in  eruption  of  third  molars,  203 
gouty,  upon  teeth,  485 
maxillary,  due  to  caries,  414 
to  necrosis,  414 
to  tooth-root,  414 
mode  of  formation,  91 


Abscess,  scars  from  treatment  of,  419 

venting  of,  93 
Acetanilid,  composition  of,  539 

uses  of,  545 
Acid,  acetic,  545 

arsenious,  546 
antidote  for,  546 
mode  of  action  of,  546 

benzoic,  546 

boric,  546 

carbolic,  547 

chromic,  547 

gallic,  547 

hydrochloric,  547 

lactic,  547 

nitric,  548 

oxalic,  548 

phosphoric,  548 

salicylic,  54S 

sodium  phosphate  in  erosion,  origin  of,  251 

sulfuric,  548 
aromatic,  548 

sulfurous,  549 

tannic,  549 

trichloracetic,  545 
Acids,  545 

Aconite  tincture,  549 
Aconitine,  550 

ointment  of,  550 
Actinomycosis,  522 
Agenesia,  51 
Alcohol,  ethyl,  550 

methyl,  550 

phenyl.     (See  Carbolic  acid.) 
Alexins,  50 
Alpha-naphtol,  564 
Alum,  potash,  550 

ammonia,  550 
Alveolar  atrophy,  457,  458 

caused  by  salivary  calculus,  453 

process,  form  of,  161 
growth  of,  123 
Amalgam-fillings,  poisoning  by,  314 
Amalgams,  properties  of,  314 
Ameloblasts,  contents  of,  114 
Ammonium  carbonate,  551 

hydrate,  551 

nitrate,  551 
Ammonol,  551 
Amceba,  functions  of,  19-21 
Amyl  nitrite,  551 
Anaemia,  69 

effects  of,  34 
Anfesthetics,  537 

local,  539 

575 


576 


INDEX. 


Anaesthetics,  local,  composition  of,  540 

mode  of  action  of,  537 
Analgesics,  529 

definition  of,  538 
Angina  pectoris,  nature  of,  76 
Anodynes,  action  of,  537-539 
Antifebrin,  545 
Antipyrin,  551 
Antiseptic  oils,  565 
Antiseptics,  529 

alcohols  and  derivatives  as,  531 

caustic  alkalies  as,  531 

classification  of,  530 

as  dentifrices,  324 

essential  oils  as,  531 

halogens  and  their  compounds  as,  531 

heat  as,  531 

mineral  acids  as,  531 

mode  of  action  of,  530 

nascent  oxygen  as,  531 

organic  acids  as,  531 

salts  of  metals  as,  530 

strength  admissible  in  mouth- washes,  325 
Antrum,  discharge  of  abscess  into,  400-412 

empyema  of,  treatment  of,  418,  419 
Aphtha,  516 
Aplasia,  51 
Aristol,  552 
Arsenic,  absorption  of,  by  pulp,  368 

accidents  with,  377 
treatment  of,  377 

antidotes  for,  377 

effects  of  combinations,  371 
of  combining  coagulants,  371 
upon  pulps,.  368 
upon  nerve-fibres,  368 
when  nodules  are  present,  370 

form  in  which  used,  371 

guarding  gum-tissue  from,  371 

idiosyncrasies  as  to  action  of,  371 

in  immature  teeth,  370 

to  lessen  pain  of  application  of,  373 

mode  of  applying,  372 

rules  for  using,  371 

in  temporary  teeth,  370 

variations  as  to  action  of,  370 
Arsenical  pastes,  367 
Arteries,  calcification  of,  66 

nervous  control  of,  76 

terminal,  occlusion  of,  72 
Astringents,  540 

mode  of  action  of,  541 
Atheroma,  66 
Atrophy,  causes  of,  61 

nature  of,  61 

physiological,  61 
Atropia,  chemical  relations  of,  540 

BACILLI,  39 
Bacillus  tuberculosis,  effects  of,  64 
Bacteria,  classification  of,  39 
conditions  of  life  of,  39 
decompositions  eflfected  by,  43 
eflfects  of,  on  tissues,  190 
infective,  of  mouth,  511 
ingestion  of,  by  amoebae,  20 
mode  of  entrance  to  body,  90 


Bacilli  of  the  mouth,  45-47 

pathogenic,  40 

physiology  of,  38 

place  of,  in  nature,  38 

pyogenic,  45 

saprophytic,  40 

waste-products  of,  42,  43 

where  found,  44,  45 
Bacteriology,  history  of,  37 
Bell  on  caries,  265 
Benzoyl  as  an  analgesic  nucleus,  540 
Beta-naphtol,  564 
Bicuspids,  architecture  of,  143 

impacted,  237 

imprisoned,  229 

mechanics  of,  170 

surgical  relations  of,  160 
Black  on  structure  of  teeth,  279 
Black's  1-2-3  mixture,  573 
Blastomycetes,  pathogenic,  in  mouth,  511 
Bleaching-powder  (Kirk's),  549 
Blood,  abnormal  composition  of,  69 

alterations  in,  71 

coagulation  of,  71,  72 

conditions  of,  69 

effects  of  waste-products  on,  69 

number  of  red  corpuscles  of,  70 

office  of  oxygen  in,  69 
of  red  corpuscles  of,  70 

phagocytes  of,  73 

-supply,  lessened,  causes  of,  74 

-vessels,  degenerative  changes  in,  63 
Bodecker,  theories  of,  272 
Bone,  first  appearance  of,  in  Jaw,  108 

interstitial  development  of,  108 
Borax,  552 
Boroglycerin,  553 
Bridgmann  on  caries,  266 
Bromid  of  sodium,  553 

of  potassium,  553 

pAFFEIN,  553 

\J  Calcareous  degeneration,  65 
effects  of,  330 

Calcification,  tubular,  causes  of,  330 

Calcium  carbonate,  553 
chlorid,  553 

■    hypochlorite,  553 
hypophosphites,  553 
oxid,  553 

Calco-globulin,  113 
deposits  in  pulp,  336 

Calco-spherites,  113 

Calculi,  subgingival,  456 

as  cause  of  pyorrhoea,  457 
composition  of,  456,  457 
eflfects  of,  457,  458 
occurrence  of,  457 

Calculus,  salivary,  447 
causes  of,  448 
eflfects  of,  452 
formation  of,  449,  450 
upon  incisors,  origin  of,  451,  452 
upon  molars,  origin  of,  451 
occurrence  of,  447 
prognosis  of  eflfects  of,  454 
in  scales  beneath  gum,  452 


INDEX. 


577 


Calculus,  .salivary,  structure  of,  452 
treatment  of,  454 
use  of  acids  to  retuove,  454 
varieties  of,  447 
Camphor  liniment,  554 

spirits  of,  554 
Caniplio-)iliPnique,  554 
Canal -filling,  376 
Canals,  root-,  lining  of,  with  silver  nitrate, 

390 
Cancer,  59 
Cancrum  oris,  517 
Canker  sore,  516 
Cantharides,  554 
Capsicum,  554 

and  myrrh,  555 
Carcinomata,  59 

Caries,   arrangement  of    teeth   influencing, 
280 

Bell's  theory  of,  262 

Bridgmann's  theory  of,  266 

casts  of  tubules  in,  301 

cavity  preparation,  316 

of  cementum,  302 

changes  of  saliva  influencing,  280 

clinical  history  of,  281 

deep-seated,  317 

defects  of  teeth  and,  218 

dental,  264 

acids  in,  265,  266-272 

of  dentin,  298 

destruction  of  dentin-matrix  in,  300 

diagnosis  of,  304 

dressing  enan)el-surfaces,  315 

effects  of  disease  upon,  277 
upon  pregnancy,  276 
of  starclies  on,  274 
of  sugars  on,  274 

of  enamel,  291 

endangered  pulps  in,  318 

exciting  causes  of,  273 

extensive,  with  small  orifices,  315 

fermentation  and,  265 

formation  of  cavities,  305 

forms  of  teeth  influencing,  279 

fourth  stage  of,  treatment  of,  319 

Fox's  theory  of,  265 

general  predisposing  causes  of,  276 

history  of  theories  of,  264 

Hunter's  theory  of,  265 

incej)tion  of,  281 

inflannnatory  theory  of,  265 

influence  of  heredity  upon,  277 

invasion  of  tubules,  300 

lactic  acid  in,  270 

leaving  softened  dentin  in,  318 

Leber  and  Rottenstein' s  theory  of,  268 

local  predisposing  causes  of,  277 

Miller  on  compatibilitv  theorv  of,  266 

Miller's  theory  of,  268 

Milles  and  Underwood's  theory  of,  268 

at  necks  of  teeth,  289 

Palmer's  theory  of,  266 

pathology  of,  290 

pigmentation  in,  302 

predisposing  causes  of,  275 

prognosis  of,  312 

37 


Caries,  prophylaxis  of,  322 

rapidity  of  its  progress,  287 

Kobertson's  theory  of,  265 

second  stage  of,  treatment  of,  317 

secondary  dentin  in,  333 

signs  of,  304 

situations  in  which  found,  282 

spontaneous  arrest  of,  288 

sterilization  of  dentin  in,  318 

sugars  as  a  cause  of,  274 

superficial,  treatment  of,  315 

symptoms  of,  305 

third  stage  of,  treatment  of,  318 

Tomes'  theory  of,  265 

transverse  process  of,  301 

treatment  of,  313 

tubules  of  dentin  in,  300 

usually  absent  in  erosion,  289 

variations  in  progress  of,  288 

Watt's  theory  of,  267 
Cartilage  of  Meckel,  104 
Caryophyllum,  oil  of,  565 
Caseation,  64 
Cassia,  oil  of,  565 
Casts  of  tubuli,  301 
Cataphoresis,  544 

in  canal-treatment,  391 

cocain,  311 

in  pulp-extirpation,  367 
Cavities,  carious,  preparation  of,  316 

lining  of,  318 
Cell- functions,  special,  23 
Cements,  acid  reaction  of,  318 
Cementoblasts,  118-139 
Cementoclasts,  139 
Cementum,  abnormalities  of,  214 

caries  of,  302 

formation  of,  117-135 

histology  of,  135 

nourishment  of,  158 
Chancre  of  mouth,  519 
Chemotaxis,  negative,  49 

positive,  49 
Chemotaxtic  properties  of  saliva,  49,  50 
Children,   difficulties    in    operating    upon, 
492 

management  of  492 
Chloral  hydrate,  555 
Chloroform,  555 

dangers  of,  in  dentistry,  538 
Chlorophyll,  properties  of,  38 
Cinnamon,  oil  of,  565 
Circulation  in  disease,  34 
Clasps,  effects  of  wearing,  245 
Clefi  palate,  104 
Cloudy  swelling,  62 
Cloves,  oil  of,  565 
Coagulation  limiting  diflFusion,  535 

-necrosis,  68 
Cobalt,  555 
Cocain,  555 

chemical  relations  of,  540 

injection  of,  formula  for,  556 
into  pulp,  367 
Cold,  effects  of,  on  vitality,  21 
Colic  in  teething,  191 
Collodion,  558 


578 


INDEX. 


Colloid  degeneration,  65 
Concrescence  of  teeth,  217 
Convulsions,  teething-,  188 
Copper  oxid,  556 

sulfate,  557 

tooth-staining  by,  256 
Coronoid  process,  growth  of,  121 
Corrosive  sublimate,  562 
Cotton,  absorbent,  preparation  of,  557 
Cough,  teething-,  187 
Counter-irritants,  use  of,  79 
Creosote,  557 
Cresols,  557 
Cuspids,  architecture  of,  142 

impacted,  236 

mechanics  of,  168 

upper,  treatment  of  impacted,  241 
Cusps,  supplemental,  217 

DEAFNESS  caused  by  dental  diseases,  507 
Degenerations,  calcareous,  65 
causes  of,  62 
colloid,  65 
fatty,  63 

causes  of,  63 
granular,  62 
hyaline,  65 
inflammatoi'y,  60 
mucoid,  65 
Dental  band,  106 
caries,  264 
cords,  107 
groove,  106 
lamina,  107 
pain  arising  from  other  diseases,  509 

origin  of,  502 
ridge,  106 
Dentifrices,  323 
tooth-pastes,  324 
tooth-soaps,  324 
use  of  antiseptics  in,  324 
Dentin,  abrasion  of,  261 
absorption  of,  263 
action  of  acids  on,  127,  146 
basis  of,  128 

calcium  salts  in,  amount  of,  145 
caries  of,  298 
acid  in,  298 

destruction  of  organic  matrix,  300 
softening  prior  to  infection,  298 
changes  with  age,  145 
chemical  nature  of,  146 
density  of,  145 
diseases,  classification  of,  260 

constructive,  260 
erosion  of,  261 

exposed,  reflex  pains  from,  502 
fibrillffi  of,  147 
formation  of,  116 
granular  layer  of,  129,  212 
hypersensitivity  of,  305 
causes  of,  306 
pathology  of,  306 
symptoms  of,  307 
treatment  of,  308 
alkalies,  309 
analgesics,  310 


Dentin,   hypersensitivity   of,   treatment   of, 
anodynes,  308 
cataphoresis,  311 
caustics,  309 
cold,  309 
dryness,  309 
obtundents,  310 
interglobular  spaces  in,  129,  212 
mineral  basis  of,  146 
organic  matter  of,  145 
physical  strength  of,  145 
resorption  of,  262 
recalcification  of,  in  caries,  300 
retrogressive  changes  in,  146 
secondary,  261,  33l 
in  abrasion,  333 
in  caries,  333 
causes  of,  332 
pathology  of,  332 
Tomes'  fibres,  129-133 
transitional,  134 
translucent,  261 
tubular  calcification  of,  330 
Dentinal  tubuli,  126 
Dentition,  hygiene  of,  185 

intestinal  disturbances  in,  186,  187 
multiple,  225 

nervous  disorders  during,  187,  188 
pathological,  185 

symptoms  of,  185-188 
treatment  of,  188-194 
process  of,  181 

pulmonary  symptoms  in,  187 
second,  195 

disorders  of,  199 
skin-disorders  in,  187 
third,  225 
Deodorants,  action  of,  530 
Devitalizing  fibi'e,  374 
Devitalization  of  pulp,  367 
Diabetes,  influence  of,  upon  caries,  277 
Diarrhcea  of  teething,  190 
Diet  of  gouty  patients,  489 
Disease-causes,  abnormal  food-supply,  33 
abnormal  physical  conditions,  35 
nature  of  exciting,  32 
poisons  as,  34 
Diseases,  causes  of,  35 
classification  of,  24 
functional,  23,  24 
general,  and  dental  caries,  277 

definition  of,  36 
immunity  from,  31,  32 
local,  definition  of,  36 
objective  evidences  of,  24 
pathology  of,  24 
predisposing  causes  of,  29,  32 
age,  30 

existing  disease,  30 
heredity,  30 
previous  disease,  31 
sex,  30 

tempei'ament,  30 
prophylaxis  of,  27 
structural,  24 
subjective  evidences  of,  24 
Disinfectants,  definition  of,  530 


INDEX. 


579 


Dobell's  solution.  552 
Dwarf  teeth,  215 

EDENTULOUS  persons,  224 
Electricity,  chemical  etiects  of,  543 
in  dental  therapeutics,  542 
physiological  effects  of,  542 
Electrolysis  in  dental  therapeutics,  543 

in  treatment  of  abscesses,  415 
Emboli,  infective,  99 
Embolus,  72 
Enamel,  abrasion  of,  245 
arrangement  of,  142-144 
caries  of,  291 

organisms  of,  292-298 
relations  of  bacteria  to,  297 
second  stage  of,  295 
situation  of  acids,  292 
cement-substance  of,  115 

solubility  of,  125 
changes  in,  after  eruption,  115 
-cracks,  242 

decalcification  of,  without  cavities,  294 
dentinal  process  in,  209 
-deposition,  116 
development  of,  109 
diseases  of,  242 
faulty,  about  sulci,  209 
fracture  of,  242 
-globules,  115 
histology  of,  123 
injury  of,  243 
lines  of  cleavage  of,  244 
malformations  of,  2()G 
-organ,  evolution  of.  111 
formation  of,  108 
stellate  reticulum  of,  112 
stratum  intermedium  of,  113 
structure  of.  111 
perfect,  206 

pigmented  lines  in,  210 
-prisms,  123 

of  pulpless  teeth,  strength  of,  244 
resistance  of,  chemical,  144 

physical,  144 
-rods,"  123 

action  of  acids  on,  124 
arrangement  of,  125 
solution  of,  259 
stains  of,  255 

treatment  of,  258 
stratification  of,  210 
strength  of,  142 
striiv  of  Ketzius,  125 
striation  of,  125-210 
a  non-vital  tissue,  141 
syphilitic,  210,  211 
white  spots  in,  207 
Encapsulation  of  foreign  bodies,  54 
Encysted  teeth,  231 
Epithelioma,  59 
Ergot,  558 
Erigeron,  558 
Erosion,  247 

appearances  of,  253 
causes  of,  248-251 
causes  of  ajjpearance,  252 


Erosion  of  dentin.  2(31 

diagnosis  of,  254 

morbid  anatomy  of,  252 

symptoms  of,  254 

treatment  of,  254 
Eruption,  periods  of,  182 
Eruptive  fevers,  teeth  of,  211 
Ether,  ethylic,  558 
Ethyl  chlorid,  558 
Eucain,  558 

chemical  relations  of,  540 
Eucalyptus,  oil  of,  5(35 
Eugenol,  565 

Evolution,  higher,  of  cell-properties,  22 
Exostosis  of  tooth-roots  (hypercementosis), 

428 
Exudations,  inflammatory,  178 
Eve,  diseases  of,  caused  bv  dental  diseases, 
508 

FATTY  degeneration,  63 
in  inflammation,  64 
in  tumors,  64 
of  vessels,  64 
Fermentation,  conditions  of,  42 

nature  of,  41 
Ferments,  organized,  44 

unorganized,  44 
Fever,  95 
cau.ses  of,  95 
classes  of,  95 

pathology  and  morbid  anatomy  of,  95 
prognosis  of,  95 
symptoms  of,  95 
treatment  of,  95 
Fibres,  Sharpey's,  in  ceraentum,  136 
Fibrillw  of  dentin,  147 
Filling-materials,  properties  of,  313 
Fistida,  artificial,  establishing.  404 
Follicle,  dental,  109 
Follicles,  labial,  250 

formation  of,  410 
Follicular  wall,  111 
Foreign  bodies,  fate  of,  in  tissues,  54 
Formalin,  559 
Fox  on  caries,  265 

Fungous  pulp.     (See  Pulp,  Hypertrophy  of.) 
Fused  teeth,  216 
pulps  of,  217 

GANGRENE,  dry,  68 
moist,  6S 
of  mouth,  517 
of  pulp,  381 
Gaultheria,  oil  of,  565 
Geminous  teeth,  217 
Germicides,  mode  of  action  of,  531 
Giantism  of  teeth,  214 
Gingival  organ,  137 

Gingivitis,  caused  by  foreign  bodies,  445,  446 
local,  causes  of,  445 
marginal,  444 
causes  of,  444 
and  general  diseases,  445 
prognosis  of,  446 

relations  with  pericemental  diseases,  446 
symptoms  of,  446 


580 


INDEX. 


Gingivitis,  treatment  of,  446,  447 
Glycerin,  559 

Gold,  advantages  of,  as  a  filling,  314 
Gout,  causative  of  pericemental  irritation, 
436 
points  of  attack  of,  482 
-poison,  mode  of  action,  480 

selective  action  of,  482 
treatment  of,  487 
Gouty  diathesis  and  ei'osion,  249 

pericementitis,  477 
Granulation-tissue,  87 
Green  stain,  257 
causes  of,  257 
coloring-matter  of,  258 
decalcification  under,  257 
Grooved  teeth,  215 
Guaiacol,  559 
Guaia-cocain,  559 

Gum,  inflammation  of,  in  dentition,  202 
-lancing,  192,  193 

hemorrhage  after,  194 
Gumma  in  mouth,  521 
Gums,  structure  of,  137 
Gutta-percha,  properties  of,  315 

HEMOGLOBIN,  deficiency  of,  70 
Hamamelis,  559 
Harelip,  cause  of,  103 
Harting  on  calco-globulin,  113 
Hemorrhagic  infarct,  72,  73 
Herbst  method  of  treating  pulps,  372 
Hernia  of  pulp,  223 
Hertwjg,  O.,  on  protoplasm,  18,  19 

root-sheath  of,  118-136 
Homatropin,  its  chemical  relations,  540 
Honeycombed  teeth,  212 
Hunter  on  caries,  265 
Hutchinson  teeth,  218 
Hyaline  degeneration,  65 
Hydrogen  dioxid,  560 
Hydronaphtol,  564 
Hypersemia,  69-75 
arterial,  77 
causes  of,  77 
exudations  in,  78 
pathology  of,  78 
results  of,  78 
symptoms  of,  78 
treatment  of,  78,  79 
a  predisposition  to  infection,  91 
of  pulp,  active,  341 
venous,  79 
causes  of,  79 
morbid  anatomy  of,  79 
pathology  of,  79 
symptoms  of,  79 
treatment  of,  80 
Hypercementosis,  428 
causes  of,  428 

causing  reflex  neuralgia,  505 
diagnosis  of,  431 
histology  of,  431 
morbid  anatomy  of,  429 
pathology  of,  429 
symptoms  of,  431 
treatment  of,  432,  433 


Hypernutrition,  eflfects  of,  52 
Hyperplasia,  52 

causes  of,  52,  53 

from  disuse,  53 

from  overwork,  53 
Hyperpyrexia,  95 
Hypersensitivity  of  dentin,  305 
Hypertrophy,  52 
Hypodermatic  medication,  544 
Hyponutrition,  effects  of,  61 

"IMPACTED  cuspids,  236 
i  bicuspids,  237 

incisors,  237 

teeth,  231 

causing  neuralgia,  507 

third  molars,  lower,  231 
upper,  235 
Imprisoned  bicuspids,  229 
Incisors,  architecture  of,  142 

impacted,  237 

mechanics  of,  168 

surgical  relations  of,  159 
Incompatibles  in  prescriptions,  541 
Infarct,  hemorrhagic,  72,  73 
Infarction  of  pulp,  347 
Inflammation,  catarrhal,  84 

causes  of,  80,  83 

changes  in,  81 

definition  of,  80,  83 

diapedesis  in,  82 

exudations  of,  81 

fatty  degeneration  in,  64 

induced  by  stieptococci,  92 

infective,  89 

interstitial,  84 

MetchnikofT's  theory  of,  82-89 

parenchymatous,  84 

pathology  of,  81 

phagocytosis  in,  82 

regeneration  after,  85 

serous,  84 

symptoms  of,  83 

terminations  of,  82 

treatment  of,  84 
bloodletting  in,  85 
cold  in, 

varieties  of,  83,  84 
Inflammatory  degeneration,  60 

origin  of  cells,  82 
Inoculation,  history  of,  32 
Insanity  due  to  dental  diseases,  509 
Interglobular  spaces,  129,  147,  212 
Interstitial  inflammation,  83 
Intestinal  poisons,  effects  of,  71 
Intoxication,  septic,  95 
lodids,  560 
lodin,  560  _ 

compounds,  action  of,  as  antiseptics,  535 
Iodoform,  560 
lodol,  561 
Iron  salts,  561 

tooth-staining  by,  256 
Ischsemia,  69 

JAWS,  architecture  of,  173 
development  of,  101 


INDEX. 


581 


Jaws,  earliest  appearance  of,  102 
mode  of  growth  of,  102 

KARYOKINESIS,  21 
Kino,  tincture  of,  561 
Kirk  on  origin  of  acid  in  erosion,  251 
Krameria,  tincture  of,  561 

LABIAL  follicles,  250 
glands,  250 
secretion  of  250 
Lateral  incisors,  upper,  non-development  of, 

165 
Lead, 

acetate  as  an  astrinyent,  541 
tooth-staining  by,   256 
-water  and  laudanum, 
Leeuwenhoek  on  bacteria,  47 
Leucocytes,  varieties  of,  73 
Leucocytosis  in  suppuration,  74 
Liquefaction-necrosis,  68 
Listerism,  37 

Litliium  bitartrate  in  gout,  488 
Lymphailenitis  following  dental  abscess,  401 
Lymphatic  infection,  98 
Lysol,  501 

MAGNESIUM,  562 
hydrate,  562 
hydrate  in  erosion,  255 
sulfate,  562 
Malformations  of  teeth,  206 
Malpositions  of  teeth,  227 

causes  of,  228 
Manganese,  tooth-staining  by,  256 
Mastication,  mechanism  of,  176 
Materia  medica  of  dentistry,  classification 

of,  529 
Maxilla,  inferior,  architecture  of,  173 
blood-supply  of,  163 
mechanics  of,  175 
size  of,  at  different  ages,  120 
Maxillie,  later  develoinnent  of,  119 
superior,  architecture  of,  173 
blood-supply  of,  164 
growth  of,  121 
Meckel's  cartilage,  104 

atrophy  of,  104-119 
Membrane,  Nasmyth's,  141 
Menthol,  562 

Mercurial  pericementitis,  436 
Mercurialisra  from  amalgam,  314 
Mercuric  chlorid  in  putrefaction,  532 
Mercury  bichlorid,  562 
oxid,  ointment  of,  563 
sulfid,  563 

tooth-staining  by,  256 
Metallic  salts,  germicidal  action  of,  534 
Metastasis  of  tumors,  60 
Metchnikofl'  on  phagocytosis,  48,  49 
Metchnikoff's  theory  of  inflammation,  82-89 
Methyl  chlorid,  563 
Micrococci,  classes  of,  39 
Miller  on  caries,  268 

experiments  of,  in  fermentation,  269 
Milles  and  Underwood  on  caries,  268 
Molars,  first,  eruption  of,  197 


Molars,  fourth,  225 

first,  premature  loss  of,  efl'ects  of,  230 

care  of,  231 
mechanics  of,  170 
pathological  eruption  of,  201 
causes  of,  201 
treatment  of,  201 
permanent,  eruption  of,  201 
roots,  anatomical  relations  of,  161 
second,  eruption  of,  199 
surgical  relations  of,  160 
third,  architecture  of,  143 
late  eruption  of,  224 
lower,  extraction  of,  204 
impaction  of,  231 
Morphia,  563 

Motor  disturbances  of  dental  origin,  508 
Mouth,  bacteria  of,  pathogenic,  48 
ferments  of  275 
infection  from,  99 
infections  of  and  from,  511 
phagocytosis  in,  99 
Mucin,  coagulation  of,  by  lactic  acid,  281, 448 
Mucoid  degeneration,  65 
Mucous  patches,  520 
Mummification  of  pulp,  378 
Muscles,  stiflhess  of,  in  dentition,  202 
Myrtol,  565 

NAPHTHALIN,  564 
Naphtol,  564 
Nasmyth's  membrane,  116-141 

and  caries,  278 
Necrobiosis,  68 
Necrosis,  66 

causes  of,  66 

coagulation-,  68  ' 

in  eruptive  fevers,  199 

of  inferior  maxilla,  66 

liquefaction-,  68 

of  lower  jaw,  66 

nature  <>f,  67 

predisposing  factors  in,  67 
Nerve,  fifth  cranial,  plan  of,  501 

-terminals  in  pulp,  135,  148 
Nerves,  trophic,  35 

vasomotor,  35 
Nervous  disorders  of  teething,  treatment  of, 

191, 192 
Neumann,  sheaths  of,  127 
Neumann's  sheaths,  solubility  of,  260 
Neuralgia  caused  by  impacted  teeth,  507 

of  dental  origin,  500 

from  dental  sources,  mechanism  of,  505 

from  hypei'cementosis,  432 

from  pulp  diseases,  location  of  pain,  504 
Neuralgias,  reflex,  from  pulp  diseases,  503 
Nickel,  tooth-staining  by,  256 
Nitrous  oxid,  565 
Nodules,  pulp-,  334 

eflects  of  arsenic  in  cases  of,  370 
Noma,  517 

pathology  of,  517 
Nucleus,  division  of,  21 

OBTUNDENTS,  definition  of,  538 
of  dentin,  310 


582 


INDEX. 


Occlusion,  laws  of,  176 

plane  of,  177 
Odontitis  infantum,  186 
Odontoblasts,  131-133 

arrangement  of,  132,  133 

atrophy  of,  156 

effects  of  stimulation  on,  155 

function  of,  117 

penetrating  enamel,  117 

relations  of,  with  nerve-terminals,  148 
Odontoclasts,  139 

office  of,  198 
Odontomes,  220 

classification  of,  221 

origin  of,  221 

treatment  of,  223 
Oi'dium  albicans,  511 
Oil  of  cassia,  565 

of  cinnamon,  565 

of  cloves,  565 

of  eucalyptus,  565 

of  gaultheria,  565 

of  myrtle,  565 

of  thyme,  565 
Oils,  antiseptic,  565 

essential,  action  of,  as  obtundents,  540 
1-2-3  mixture  (Black),  573 
Ord  on  calco-globulin,  113 
Organs,  nature  of,  23 
Osteoclasts,  139 
Osteodentin  in  pulp,  339 
Osteomyelitis,  91 

causes  of,  94 

morbid  anatomy  of,  94 

pathology  of,  94 

symptoms  of,  94 

treatment  of,  95 
Oxidation  in  cells,  23 
Oxygen,  nascent,  565 

PAIN,  dental,  referred  to  distant  nerves, 
507 
reflex,  nature  of,  500 
Palate,  cleft,  104 

development  of,  103 
Palmer  on  caries,  266 
Paraffin,  566 

as  a  canal-filling,  376 
Parasitic  bacteria,  40 
Parenchymatous  inflammation,  83 
Pastes,  mummifying,  380 
Pasteur  on  bacteria,  37 
Pericementitis,  acute,  bloodletting  in,  404 
septic  apical,  394 
treatment  of,  402 
apical,  chronic,  non-septic,  427 
causes  of,  427 
diagnosis  of,  428 
effects  of,  428 
prognosis  of,  428 
symptoms  of,  427,  428 
treatment  of,  428 
beginning  at  apex,  394 
upon  deciduous  teeth,  498 
general  aseptic,  435 
acute,  435 
causes  of,  435 


Pericementitis,  general  aseptic,  acute,  clin- 
ical history  of,  435 
diagnosis  of,  436 
prognosis  of  436 
symptoms  of,  435 
treatment  of,  436 
chronic,  437 
causes  of,  437 
gouty,  477 

clinical  history  of,  477 
concretions  of,  485 
definition  of  condition,  477 
diagnosis  of,  480 
earliest  evidences  of,  478 
features  of,  479 
history  of  theory,  477 
pathology  of,  483 
points  of  attack,  485 
prognosis  of,  486 
symptoms  of,  477 
mercurial,  436 

non-septic,  classification  of,  423 
septic  apical,  chronic,  407 
diagnosis  of,  412 
non-purulent,  420 
symptoms  of,  421 
treatment  of,  421 
causing  reflex  pains,  506 
sedatives  in,  404 
traumatic,  acute,  423-427 
causes  of,  423,  424 
clinical  history  of,  425 
diagnosis  of,  425 

pathology  and  anatomy  of,  425,  426 
prevention  of,  424 
symptoms  of,  425 
treatment  of,  426,  427 
due  to  root-perforation,  427 
Pericementum,  apical,  139 
arrangement  of  fibres  of,  137 
cells  of,  139 

classification  of  diseases  of,  393 
diseases  of,  diagnosis  of,  394 

evidences  of,  393 
epithelium  in,  139 
functions  of,  136-140 
histology  of,  136-140 
as  a  ligament,  138 
nerves  of,  140-158 
nerve-terminations  in,  140 
office  of,  157 

Pacinian  corpuscles  in,  140 
the  tactile  organ  of  the  teeth,  146 
vascular  supply  of,  157 
vessels  of,  239 
Periosteum,  first  evidences  of,  108 
Periostitis  in  dental  abscess,  406 

infective,  95 
Peroxid  of  hydrogen,  560 
Phagedenic  pericementitis,  460-468 
alveolar  process  in,  472 
causes  of,  469 
definition  of,  469 
diagnosis  of,  473 
earliest  evidences  of,  469,  470 
gum-atrophy  in,  473 
morbid  anatomv  of,  471 


INDEX. 


583 


Phagedenic  pericementitis,  pathology  of,  471 
prognosis  of,  474 
recession  of  gum-raargin  in,  470 
sponge-grafts  in,  476 
symptoms  of,  469,  470 
tooth-movement  in,  469 
treatment  of,  474  r 

Phagocytes,  73 
Phagocytosis,  history  of,  48 
in  inflammation,  82-89 
Metclniikoffon,  48,  49 
in  tiie  mouth,  99 
Pharmacopcvia,  dental,  545 
Plienacetin,  566 
Plienol  sodiqiie,  569 

Physical   conditions,   abnormal,  as   disease- 
causes,  35 
Pigmentation  in  caries,  302 
Piperazin  in  gout,  488 
Pitted  teetli,  215 
Plants,  classification  of,  38 
Plenciz  on  bacteria,  37 
Pletiiora,  asthenic,  75 

sthenic,  75 
Pneumococcus  in  alveolo-dental  abscess,  395 
Potassium  bromid,  553 
carbonate,  567 
chlorate,  567 
hydrate,  567 
iodid,  ointment  of,  567 
salts,  action  of,  566 
Pregnancy,  effects  of,  upon  teeth,  146 

upon  caries,  276 
Pre-maxilla,  origin  of,  103 
Primitive  teeth,  215 
Processes  of  Tomes,  147 
Prophylaxis  of  disease,  27 
Pseudopodia  of  amoebae,  19 

of  leucocytes,  20 
Pulp,  abscess  of,  357 
arteries  of,  135,  156 
calcareous  degeneration  of,  334 
calcific  degeneration  of,  338 
causes  of,  338 
pathology  of,  339 
-capping,  321 

materials  used,  321 
results  of,  322 
capillaries  of,  156 
-chambers,  148 
forms  of,  149,  150 
resorption  of  walls  of,  365,  366 
changes  in  matrix  of,  134 
chronic  degenerations  of,  362 
cocain  injections  into,  367 

-cataphoresis  in,  367 
congestion  of,  346 
degenerations  of,  chronic,  symptoms   of, 

366 
deposits  of  calco-globulin  in,  336 
destruction  of,  by  arsenic,  367 

by  caustics,  367 
devitalization  of,  367 
analgesics  in,  374 
anodynes  in,  374 
arsenic  in,  367 
cobalt  in,  372 


Pulp,  devitalization  of,  removal  after,  374 
diseases  of,  causing  reflex  neuralgias,  603 

classification  of,  327 
distinction  of  deposits  in,  339 
divisions  of,  148 
effects  of  arsenic  upon,  368-371 
exposure  of,  320 
diagnosis  of,  320 
prognosis  of,  320 
treatment  of,  321 
extirpation  of,  treatment  of  canals  after 

376 
-fibres,  nature  of,  134 
fungous,  364 

polypus  of,  364 
gangrene  of,  381 
dry,  381 

causes  of",  381 
pathology  of,  381 
symptoms  of,  382 
treatment  of,  382 
moist,  383 
causes  of,  383 
with  open  cavities,  384 
without  caries,  386 
organisms  in,  384 
partial,  387 

pericementitis  following,  388 
in  pyorrhoea,  386 
symptoms  of,  386 
treatment  of,  387 
under  fillings,  385 
hemorrhagic  infarction  of,  347 
hernia  of,  223 
histology  of,  131-135 
hypersemia  of,  active,  341 
anatomy  of,  342 
bloodvessels  in,  342 
causes  of,  341 
diagnosis  of,  344 
idiopathic,  346 
pathology  of,  342 
prognosis  of,  344 
symptoms  of,  341 
treatment  of,  345 
passive,  346 

pathology  of,  346 
prognosis  of,  347 
symptoms  of,  347 
treatment  of,  347 
hypertrophy  of,  364 
calcification  of,  365 
diagnosis  of,  366 
pathology  of,  364,  365 
transplantation  of  epithelium  in,  365 
treatment  of,  366 
infarction  of  73 
inflammation  of,  348 

chronic,  362 
malformations  of,  213 
mummification  of,  378 
nerves  of,  132-135 
neural  svstem  of,  135 
-nodules,  334 

influence  of,  upon  action  of  arsenic,  370 
occurrence  of,  335 
pathology  of,  335 


584 


INDEX. 


Pulp-nodules,  structure  of,  335 
symptoms  of  small,  337 

of  large,  337 
treatment  of,  339 
Pulp,  no  lymphatics  in,  131 
osteodentin  in,  339 
partial  removal  of,  378 

Herbst  method,  372 
putrescence  of.    (See  Moist  gangrene.) 
reflection  of  sensations,  502 
reflex  pains  in,  157,  502 
refrigeration  of,  367 
reticular  atrophy  of,  362,  363 
sclerosis  of,  362 

treatment  of,  363 
sensory  function  of,  156 
stroma  of,  157 
structure  of  matrix,  134 
suppuration  of,  354 
bacteria  in,  354-357 
causes  of,  354 
diagnosis  of,  359 
evacuation  of  pus  in,  361 
morbid  anatomy  of,  355 
prognosis  of,  359 
symptoms  of,  359 
treatment  of,  360 
ulceration  of,  356 
vascular  system  of,  134,  135 
veins  of,  132,  134,  156 
-walls,  resorption  of,  263 
Pulpitis,  acute,  348 
causes  of,  349 
diagnosis  of,  352 

pathology  and  morbid  anatomy  of,  350 
prognosis  of,  353 
symptoms  of,  352 
treatment  of,  353 
chronic,  362 

hypertrophic,  364 
in  deciduous  teeth,  496 
Pulps,  absence  of  response  in,  330 
constructive  diseases  of,  330 
reasons  for  reflex  pains  in,  328 
shapes  of,  151-155 
thermal  test  of,  328 
Pulse,  75 

variations  of,  76,  77 
Pus,  burrowing  of,  in  alveolar  abscess,  412 
Putrefaction  of  tissues,  68 
Pyaemia,  98 
causes  of,  98 
in  dental  abscess,  402 
of  dental  origin,  523 
symptoms  of,  99 
treatment  of,  99 
Pyogenic  bacteria,  45 
cocci,  90 

membrane  in  dental  abscess,  407 
Pyorrhoea  alveolaris.  459 
bacteria  in,  459 
beginning  at  gum-margin,  460 
causes  of,  460 
clinical  history  of,  460 
diagnosis  of,  464 
morbid  anatomy  of,  462 
pathology  of,  462 


Pyorrhoea    alveolaris    beginning    at    gum- 
margin,  prognosis  of,  465 
symptoms  of,  460 
treatment  of,  465-468 

classes  of,  459,  460 

death  of  pulps  in,  461 

differential  diagnosis  of,  464,  465 

distinctions  of  classes,  460 

meaning  of,  459 

mode  of  scaling,  466 

nature  of,  444 

splints  for  teeth  in,  465,  466 

use  of  drugs  in,  467,  468 

varieties  of,  459 
Pyrozone.     (See  Hydrogen  dioxid.) 

QUERCUS,  567 
Quillaia,  567 

RACHITIS,  eflTects  of,  upon  dentition,  194 
Radiograph  of  impacted  teeth,  239 
Rainey  on  calco-globulin,  113 
Reflex  pains,  dental,  500 

from  general  diseases,  500 
diagnosis  of,  506 
facial,  origin  of,  503 
from  pericemental  diseases,  503 
from  pulp  diseases,  503 
referred  to  teeth,  509 
Reflexes  of  dental  origin,  500 
Refrigeration  of  pulp,  367 
Regeneration  of  blood-vessels,  87 
of  epithelium,  88 
of  tissues,  85 
Resorcin,  567 
Resorption,  61 
in  dentition,  181 
of  roots,  failure  in,  200 
Retzius,  striae  of,  125,  210 

in  erosion,  253 
Ridge,  dental,  106 
Robertson  on  caries,  265 
Robinson's  remedy,  567 
Root,  growth  of,  118 
Root-apex,  amputation  of,  416 

-sheath  of  Hertwig,  118 
Roots,  malformations  of,  218 
perforated,  amputation  of,  427 
treatment  of,  427 

SACCHARIN,  567 
Saliva,  chemotactic  property  of,  49,  50 
composition  of,  448 
deposits  of  calcium  salts  from,  449 
hypersecretion  of,  450 
reaction  of,  448 
toxicity  of,  513 
Salol.  568 
Salufer,  570 
Sandarac  varnish,  570 
Saprophytic  bacteria,  40 
Scaling  teeth,  454 
Schizomycetes,  38 
Sedation,  effects  of,  22 
Septic  diseases  of  dental  origin,  522 
infection,  nature  of,  90 
intoxication,  95 


INDEX. 


585 


Septic  intoxication  in  childi'en,  498 
Septicjemia,  96 

causes  of,  U7 

in  dental  abscess,  402 

symptoms  of,  97 

treatment  of,  98 

varieties  of,  96 
Septicopyemia,  98 
Serres,  glands  of,  137 
Serum,  blood-,  germicidal  power  of,  50 
Sharpey,  fibres  of,  in  cementum,  136 
Sheaths  of  Neumann,  127 
Shellac  varnish,  571 
Silico-fluorid  of  sodium,  570 
Silver  citrate,  b'oi,  5(39 

lactate,  569 

nitrate  as  astringent,  541 
decomposition  of,  568 

tooth-staining  by,  257 
Skiagraphy  in  diagnosis  of  impaction,  239 
Skin-eruption  in  teething,  treatment  of,  189 
Sodium  bicarbonate,  509 

borate,  569.     (See  Borax  also.) 

bromid,  553 

dioxid,  569 

reactions  of,  536 

phenate,  569 

salicylate  in  gout,  488 

silico-fluorid,  570 

sulfite.  569 
Sozoiodol,  570 
Spirillfe,  39 

Starch,  synthesis  of,  38 
Starches,  effects  of,  in  caries,  274 
Stellate  reticulum,  112 

atrophy  of,  115 
Steresol  varnish,  571 
Sterilization,  dental,  523 
of  apparatus,  525 
of  field  of  operation,  526 
of  instruments,  525 
of  operator,  524 
Stimulation,  efl^ects  of,  21 
Stomatitis,  aphthous,  516 

catarrhal  infective,  514 

causes  of,  513 

classification  of,  514 

occurrence  of,  513 

simple,  treatment  of,  514 

svmptomatic,  515 

teething,  189,  190 

ulcerative,  515 
local,  516 

varieties  of,  513 
Stratum  granulosum,  118 

intermedium,  113 
Structural  diseases,  24 
Struma,  effects  of,  upon  dentition,  194,  195 
Subgingival  calculi,  452 
Snboxidation,  diseases  of,  445 
Sugar,  fermentation  of,  271 
Sulfo-methjeinoglobin,  256 
Supernumerary  teeth,  225 

origin  of,  226 
Suppuration,  90 

causes  of,  90 

leucocytosis  in,  74 


Suppuration,  prognosis  of,  92 
symptoms  of,  92 

general,  92 
treatment  of,  92 
Syphili-s,  effects  of,  upon  dentition,  194 
infecti\e  power  of  lesions,  518 
of  mouth,  primary,  519 
diagnosis  of,  519 
mode  of  infection,  519 
secondary,  520 
sterilization,  527 
tertiary,  521 
stages  of,  518 
Syphilitic  affections  of  mouth,  518 
enamel,  211 
teeth,  219 

TEETH,  abrasion  of,  245 
treatment  of,  246 
absence  of,  congenital,  224 
architectural  designs  of.  142 
calcic  basis  of,  113 
cleansing  after  scaling,  456 
concrescence  of,  217 
deciduous,  abrasion  of,  493 
treatment  of,  494 
canal-filling,  498 
caries  of,  494 
cavity  preparation  in,  495 
deposits  ujiou,  491 
destroying  pulps  of,  495 
diseases  of,  491 

effects  of  premature  loss  of,  200 
extraction  of,  effects  of,  220,  228 

delayed,  eff^ects  of,  229 
green  stains  upon,  492 

importance  of  treating,  493 
pericementitis  of  498 
extraction  for,  499 
treatment  of,  498 
pulp-exposure  in,  494 
treatment  in,  495 
sensitivity  of,  491 
pulps  of  diseases  of,  496 
removal  of  pulps  of,  497 
silver  nitrate  in,  495 
defects  of,  and  caries,  278 
deficiency  in  number  of,  224 
disuse  of,  absolute,  results  of,  442 
pathology  of,  443 
prognosis  of,  443 
treatment  of,  443 
partial,  causes  of,  441 
clinical  history  of,  441 
diagnosis  of,  442 
pathology  of,  441 
prognosis  of,  442 
treatment  of,  442 
dwarf,  215 
effects  of  eruptive  fevers  upon,  199 

of  gestation  upon,  276 
encysted,  231 
eruption  of,  180 
causes  of,  180 
process  of,  181 
excess  of,  225 
first  evidence  of  formation,  105 


586 


INDEX. 


Teeth,  fused,  216 
geminous,  217 
giantism  of,  214 
gouty  abscess  upon,  485 

a&ections  of,  483 
grinding  of,  in  children,  494 

at  night,  247 
grooved,  215 
honeycombed,  212 
Hutchinson,  128 
impacted,  231 
diagnosis  of,  239 
symptoms  of,  238 
treatment  of,  240 
mal-occlusion  of,  causes  of,  439 
diagnosis  of,  440 
pathology  of,  439 
prognosis  of,  440 
treatment  of,  440 
malpositions  of,  227 
mechanical  weakening  of,  144 
nerves,  plan  of  distribution  of,  501 
overuse  of,  effects  of,  437 
pathology  of,  438 
treatment  of,  438 
permanent,  calcification  of,  196 
development  of,  119 

anatomical  relations  of,  196 
eruption  of,  195 
origins  of,  109 
resorption  of  roots  of,  433 
causes  of,  434 
morbid  anatomy  of,  433 
pathology  of,  433 
symptoms  of,  434 
treatment  of,  435 
pitted,  21 5 
in  pregnancy,  146 

primitive  forms  as  abnormalities,  215 
relations  of,  141 
resorption  of  temporary,  197 
sections  of,  149,  1 50 
supernumerary,  225 
suppressed,  224 
surgical  anatomy  of,  141 
syphilitic,  219 

temporary,  pulp-chambers  of,  151,  152 
twin,  217 

upper,  surgical  relations  of,  164 
Teetliing,  180 

gum-hincing  in,  192,  193 
Teratomata.  56 
Thread-fungus,  511 
Thrombus,  72 

Thrush  fungus,  development  of,  511 
Thymol,  565 
Tissues,  nature  of,  23 
Tomes  on  caries,  265 
fibres  of,  129 
granular  layer  of,  147 
processes  of,  147 
Toxalbumins,  43 
Toxicity  of  saliva,  513 
Treatment  of  alveolo-dental  abscess,  acute, 
402 
without  fistula,  409 
on  deciduous  teeth,  498 


Treatment  of  alveolo-dental  abscess,  chronic, 
409,  411,  415 
by  electrolysis,  415 
dental  caries,  313 

erosion,  254 
disuse  of  teeth,  absolute,  443 

partial,  442 
empyema  of  antrum,  418,  419 
fevers,  95 
gingivitis,  446,  447 
hyperaemia,  active,  78,  79 

passive,  80 
hypercementosis,  432,  433 
hypersensitive  dentin,  308,  309,  310 
impacted  teeth,  240 
inflammation,  84 
mal-occlusion,  440 
osteomyelitis,  95 
pathological  dentition,  188-194 
pericementitis,  general  aseptic,  436 
of  deciduous  teetii,  498 
non-septic  apical,  chronic,  421 
phagedenic,  474 
septic  apical,  chronic,  409-415 
traumatic,  426,  427 
perforated  roots,  427 
pulp-exposure,  321 
deciduous  teeth,  495 
gangrene,  dry,  382 

moist,  387 
hypersemia,  active,  345 

passive,  347 
hypertrophy,  366 
inflammation,  353 
-nodules,  339 
suppuration,  360 
pyaemia,  99 

pyorrhoea  alveolaris,  first  class,  465-468 
resorption  of  permanent  roots,  435 
salivary  calculus,  454 
septicaemia,  98 
stomatitis,  514 
suppuration,  92 
ulceration,  93 
Trichlorphenol,  570 
Trikresol,  557 

Trismus,  muscular,  in  dentition,  203 
Tropacocain,  its  chemical  relations,  540 
Trophic  nerves,  35 
Tubercle,  nature  of,  64 
Tuberculosis  of  mouth,  522 
Tubuli  of  dentin,  126 
Tumors,  54 
capsules  of,  56 
causes  of,  55 
classes  of,  54,  55 
composition  of,  55 
compound,  57 
degeneration  of,  60 
efiects  of,  55 
epithelial,  59 
evolution  of  type,  57,  58 
fatty  degeneration  of,  64 
malignant,  56,  57 
recurrence  of,  60 
benign,  56,  57 
Twin  teeth,  217 


INDEX. 


587 


ULCERATION,  93 
causes  of,  93 
treatment  of,  93 
Ulcers  caused  by  jagged  teeth,  246 
Urates,  conditions  of  deposit,  481 
excess  of,  2o0 
origin  and  effi?cts  of,  480 
Urea,  etiects  of  retained,  71 
Uric  acid,  origin  of,  249-481 

VACCINATION,  32 
effects  of,  upon  teething,  189 
Varnishes,  sandarac,  570 
shellac,  571 
steresol,  571 
Vascular  system,  disturbances  of,  69 

range  of,  disturbances,  74 
Veratrina,  572 
Veratrum  viride,  572 
Vitality,  resistance  of,  22 


Voluntary  tooth-movement,  4'J9 
ATTS  on  caries,  268 


w 

X 


-RAY  in  diagnosis  of  impaction,  239 


ZINC  chlorid,  572 
iodid,  572 
oxid,  573 
oxychlorid,  572 

properties  of,  315,  573 
oxysulfate,  573 

phosphate,  properties  ot,  315,  573 
sulfate,  573 
Zones  of  dentin  in  caries,  298 
transparent,  in  caries,  298 
Zooglea,  39 


Catalogue  of  Books 


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Progressive  Medicine. 

A  Quarterly  Digest  of  New  Methods,  Discoveries  and  Improvements  in  the  Medical  and 
Surgical  Sciences  by  Eminent  Authorities.  Edited  by  Dr.  Hobart  Amory  Hare.  In 
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ABBOTT  (A.  C).  PRINCIPLES  OF  BACTERIOLOGY :  a  Practical  Manual  for 
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ALLEN  (HARRISON).  A  SYSTEM  OF  HUMAN  ANATOMY;  WITH  AN 
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A  TREATISE  ON  SURGERY  BY  AMERICAN  AUTHORS.  FOR  STUDENTS 
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AMERICAN  SYSTEM  OF  PRACTICAL  MEDICINE.  A  SYSTEM  OF  PRAC- 
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AMERICAN  TEXT-BOOK  OF  ANATOMY.    See  Gerrish,  page  7. 

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PROSTHETIC  DENTISTRY.    Edited  by  Chables  J.  Essig,  M.D.,  D.D.S., 

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OPERATIVE  DENTISTRY.     Edited  by  Edward  C.  Kirk,  D.D.S.,  Professor 


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AMERICAN  SYSTEMS  OF  GY;NEC0L0GY  AND  OBSTETRICS.  In  treatises 
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ASHHURST  (JOHN,  JR.).     THE  PRINCIPLES  AND  PRACTICE  OF  SUR- 

GER  Y.    For  the  use  of  Students  and  Practitioners.     Sixth  and  revised  edition.     In  one 
large  and  handsome  8vo.  volume  of  1161  pages,  with  656  engravings.  Cloth,  $6 ;  leather,  $7. 

A  SYSTEM  OF  PRACTICAL  MEDICINE  BY  AMERICAN  AUTHORS.  Edited 
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A  PRACTICE  OF  OBSTETRICS  BY  AMERICAN  AUTHORS.  See  Jewett, 
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ATTFIELD  (JOHN).  CHEMISTRY;  GENERAL,  MEDICAL  AND  PHAR- 
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In  one  handsome   12mo.  volume  of  784  pages,  with  88  illustrations.     Cloth,  $2.50,  net 


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BARNES  (ROBERT  AND  FANCOURT).  A  SYSTEM  OF  OBSTETRIC  MEL- 
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BILLINGS  (JOHNS.).  THE  NATIONAL  MEDICAL  DICTIONARY.  Includ- 
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BLACK  (D.  CAMPBELL).  THE  URINE  IN  HEALTH  AND  DISEASE, 
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BROCKWAY  (FRED.  J.).    A  POCKET  TEXT-BOOK  OF  ANATOMY.    12mo. 

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BRUCE    (J.    MITCHELL).     MATERIA    MEDIC  A    AND    THERAPEUTICS. 

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PRINCIPLES  OF  TREATMENT.     In  one  octavo  volume  of  625  pages.     Just 


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BUMSTEAD  (F.  J.)  AND  TAYLOR  (R.  W.).  THE  PATHOLOGY  AND 
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page  15. 

BURCHARD  (HENRY  H.).    DENTAL  PATHOLOGY  AND  THERAPEUTICS, 

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BURNETT  (CHARLES  H.).  THE  EAR:  ITS  ANATOMY,  PHYSIOLOGY 
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Second  edition.  In  one  8vo.  volume  of  580  pages,  with  107  illustrations.  Cloth,  $4 ; 
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CARTER  (R.  BRUDENELL)  AND  FROST  (W.  ADAMS).  OPHTHALMIC 

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one  plate.     Cloth,  $2.25.     See  Series  of  Clinical  Manuals,  page  13. 

CASPARI  (CHARLES,  JR.).  A  TREATISE  ON  PHARMACY.  For  Students 
and  Pharmacists.  In  one  handsome  octavo  volume  of  680  pages,  with  288  illustrations. 
Cloth,  $4.50. 

CHAPMAN  ( HENRY  C . ) .  A  TREA  TISE  ON  HUMAN  PHYSIOL  OGY.  Xew 
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CHARLES  (T.  CRANSTOUN).  THE  ELEMENTS  OF  PHYSIOLOGICAL 
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CHEYNE  (W.  WATSON)  AND  BURGHARD  (F.  F.).  SURGICAL  TREAT- 
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CLINICAL  MANUALS.     See  Series  of  Clinical  Manuals,  page  13. 

CLOUSTON  (THOMAS  S.).  CLINICAL  LECTURES  ON  MENTAL  DIS- 
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CLOWES    (FRANK).  AN  ELEMENTARY    TREATISE    ON  PRACTICAL 

CHEMISTRY  AND  QUALITATIVE  INORGANIC  ANALYSIS.    From  the 

fourth  English  edition.  In  one  handsome  12mo.  volume  of  387  pages,  with  55  engrav- 
ings.    Cloth,  $2.50. 

COAKLEY  (CORNELIUS  G.).  THE  DIAGNOSIS  AND  TREATMENT  OF 
DISEASES  OF  THE  NOSE,  THROAT,  NASO-PHARYNX  AND  TRACHEA. 
In  one  12mo.  volume  of  526  pages,  with  92  engravings,  and  2  colored  plates.     Cloth, 

$2.75,  net. 

COATES  (W.  E.,  Jr.).  A  POCKET  TEXT-BOOK  OF  BACTERIOLOGY 
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COATS  (JOSEPH).  A  TREATISE  ON  PATHOLOGY.  In  one  volume  of  829 
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COLEMAN.  (ALFRED).  A  MANUAL  OF  DENTAL  SURGERY  AND  PATH- 
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COLLINS  (C.  P.).  A  POCKET  TEXT-BOOK  OF  MEDICAL  DIAGNOSIS. 
12mo.  of  about  350  pages.     Shortly. 

COLLINS  (H.  D.)  AND  ROCKWELL  (W.  H.,  JR.).  A  POCKET  TEXT- 
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CONDIE  (D.  FRANCIS).  A  PRACTICAL  TREATISE  ON  THE  DISEASES 
OF  CHILDREN.    Sixth  edition.     8vo.  719  pages.     Cloth,  $5.25 ;  leather,  $6.25. 

CORNIL  (V.).  SYPHILIS:  ITS  MORBID  ANATOMY,  DIAGNOSIS  AND 
TREATMENT.  Translated,  with  Notes  and  Additions,  by  J.  Henry  C.  Simes,  M.D., 
and  J.  William  White,  M.D.  In  one  8vo.  volume  of  461  pages,  with  84  illustrations. 
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Philadelphia,  706,  708  and  710  Sansom  St.— New  York,  111  Fifth  Avenue. 


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CROCKETT  (M.  A.).  ^  POCKET  TEXT-BOOK  OF  DISEASES  OF 
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CROOK  (JAMES  K.).     MINERAL  WATERS  OF  UNITED  STATES.     Octavo 

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CULBRETH  ( DAVID  M.  R. ) .  MA  TERIA  MEDIC  A  AND  PHARMA  COLOG  Y. 
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CUSHNY  (ARTHUR  R.)  A  TEXT-BOOK  OF  PHARMACOLOGY  AND 
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$3.75,  net. 

DALTON   (JOHN   C).     A  TREATISE  ON  HU3IAN  PHYSIOLOGY.    Seventh 

edition,  thoroughly  revised.  Octavo  of  722  pages, with  252  engravings.  Cloth,  $5;  leather,$6. 

DOCTRINES  OF  THE  CIRCULATION  OF  THE  BLOOD.  In  one  hand- 
some 12mo.  volume  of  293  pages.     Cloth,  $2. 

DAVENPORT  (F.  H.).  DISEASES  OF  W03IEN.  A  Manual  of  Gynecology. 
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DAVIS  (F.H.).     LECTURES  ON  CLINICAL  MEDICINE.    Second  edition.     In 

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DAVIS  (EDWARD  P.).  A  TREATISE  ON  OBSTETRICS.  For  Students  and 
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DE  LA  BECHE'S  GEOLOGICAL  OBSERVER.  In  one  large  octavo  volume  of  700 
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DENNIS  (FREDERIC  S.)  AND  BILLINGS  (JOHN  S.).  A  SYSTEM  OF 
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DERCUM  (FRANCIS  X.),  Editor.  A  TEXT-BOOK  ON  NERVOUS  DIS- 
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341  engravings  and  7  colored  plates.     Cloth,  $6 ;  leather,  $7,  net. 

DE  SCHWEINITZ  (GEORGE  E.).  THE  TOXIC  AMBLYOPIAS ;  THEIR 
CLASSIFICATION,  HISTORY,  SYMPTOMS,  PATHOLOGY  AND  TREAT- 
MENT. Very  handsome  octavo,  240  pages,  46  engravings,  and  9  full-page  plates  in 
colors.     Limited  edition,  de  luxe  binding,  $4,  net. 

DRAPER  (JOHN  C).  MEDICAL  PHYSICS.  A  Text-book  for  Students  and  Prac- 
titioners of  Medicine.     Octavo  of  734  pages,  with  376  engravings.     Cloth,  $4. 

DRUITT  (ROBERT).  THE  PRINCIPLES  AND  PRACTICE  OF  MODERN 
SURGERY.  A  new  American,  from  the  twelfth  London  edition,  edited  by  Stanley 
Boyd,  F.R.C.S.     Large  octavo,  965  pages,  with  373  engravings.     Cloth,  $4 ;  leather,  $5. 

DUANE  (ALEXANDER).  A  DICTIONARY  OF  MEDICINE  AND  THE 
ALLIED  SCIENCES.  Comprising  the  Pronunciation,  Derivation  and  Full  Explan- 
ation of  Medical,  Dental,  Pharmaceutical  and  Veterinary  Terms.  Together  with  much 
Collateral  Descriptive  Matter,  Numerous  Tables,  etc.  New  (3d)  edition.  Square  octavo 
volume  of  652  pages  with  8  colored  plates.  Just  Ready.  Cloth,  $3.00,  net;  limp 
leather,  $4.00,  net. 

DUDLEY  (E.  C).  .4  TREATISE  ON  THE  PRINCIPLES  AND  PRACTICE 
OF  GYNECOLOGY.  For  Students  and  Practitioners.  New  (2d)  edition.  In  one 
very  handsome  octavo  volume  of  717  pages,  with  453  engravings,  of  which  47  are 
colored,  and  8  full  ]iage  plates  in  colors  and  monochrome.  Just  Ready.  Cloth,  $5.00,  net  ; 
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DUNCAN  (J.  MATTHEWS).  CLINICAL  LECTURES  ON  THE  DISEASES 
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taining a  full  Explanation  of  the  Various  Subjects  and  Terms  of  Anatomy,  Physiology, 
Medical  Chemistry,  Pharmacy,  Pharmacology,  Therapeutics,  Medicine,  Hygiene,  Dietetics. 
Pathology,  Surgery,  Ophthalmology,  Otology,  Larjnagology,  Dermatology,  Gynecology, 
Obstetrics,  Pediatrics,  Medical  Jurisprudence,  Dentistry,  etc.,  etc.  By  Robley  Dtjngli- 
SON,  M.D.,  LL.D.,  late  Professor  of  Institutes  of  Medicine  in  the  Jefferson  Medical  Col- 
lege of  Philadelphia.  Edited  by  Eichaed  J.  Dunglison,  A.M.,  M.D.  Twenty-second 
edition,  thoroughly  revised  and  greatly  enlarged  and  improved,  with  the  Pronunciation, 
Accentuation  and  Derivation  of  the  Terms.  With  Appendix.  Imperial  octavo  of  about 
1400  pages.     Shortly. 

DUNHAM  (EDWARD  K.).  MORBID  AND  NORMAL  HISTOLOGY.  Octavo, 
450  pages,  with  360  illustrations.     Cloth,  $3.25,  net. 

NORMAL  HISTOLOGY.      New   (2d)   edition.     Octavo,  319  pages,  with  244 

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EDES  (ROBERT  T.).  TEXT-BOOK  OF  THERAPEUTICS  AND  MATERIA 
MEDIC  A.     In  one  8vo.  volume  of  544  pages.     Cloth,  $3.50;  leather,  $4.50. 

EDIS  (ARTHUR  W.).  DISEASES  OF  WOMEN.  A  Manual  for  Students  and 
Practitioners.  In  one  handsome  8vo.  volume  of  576  pages,  with  148  engravings. 
Cloth,  $3 ;  leather,  $4. 

EGBERT  (SENECA).  HYGIENE  AND  SANITATION.  In  one  12mo.  volume  of 
359  pages,  with  63  illustrations.     Cloth,  $2.25,  net. 

ELLIS  (GEORGE  VINER).  DEMONSTRATIONS  IN  ANATOMY.  Being  a 
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English  edition.     Octavo,  716  pages,  with  249  engravings.     Cloth,  $4.25 ;  leather,  $5.25. 

EMMET    (THOMAS   ADDIS).     THE  PRINCIPLES  AND   PRACTICE    01 

G  YNvECOL  OGY.    For  the  use  of  Students  and  Practitioners.    Third  edition,  enlarged 
and  revised.     8vo.  of  880  pages,  with  150  original  engravings.     Cloth,  $5 ;  leather,  $6. 

ERICHSEN  (JOHN  E.).     THE  SCIENCE  AND  ART  OF  SURGERY.    A  new 

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volumes  containing  2316  pages,  with  984  engravings.     Cloth,  $9 ;  leather,  $11. 

ESSIG  (CHARLES  J.).  PROSTHETIC  DENTISTRY.  See  American  Texl-books 
of  Dentistry,  page  2. 

EVANS  (DAVID  J.).  A  POCKET  TEXT-BOOK  OF  OBSTETRICS.  12mo. 
of  about  300  pages,  amply  illustrated.     Shortly. 

FARQUHARSON  (ROBERT).  A  GUIDE  TO  THERAPEUTICS.  Fourth 
American  from  fourth  English  edition,  revised  by  Frank  Woodbxjky,  M.D.  In  one 
12mo.  volume  of  581  pages.     Cloth,  $2.50.' 

FIELD  (GEORGE  P.).  A  MANUAL  OF  DISEASES  OF  THE  EAR.  Fourth 
edition.     Octavo,  391  pages,  with  73  engravings  and  21  colored  plates.     Cloth,  $3.75. 

FLINT  (AUSTIN).  A  TREATISE  ON  THE  PRINCIPLES  AND  PRACTICE 
OF  MEDICINE.  New  (7th)  edition,  thoroughly  revised  by  Fkedebick  P.  Henry, 
M.D.     In  one  large  8vo.  volume  of  1143  pages,  with  engravings.     Cloth,  $5 ;  leather,  $6. 

A  MANUAL  OF  AUSCULTATION  AND  PERCUSSION;  of  the  Physi- 
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ume of  591  pages.     Cloth,  $4.50. 

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ON  PHTHISIS :  ITS  MORBID  ANA TOMY,  ETIOL OGY,  ETC.    A  Series 


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FORMULARY,  POCKET.     See  page  1. 

FOSTER  (MICHAEL).  A  TEXT-BOOK  OF  PHYSIOLOGY.  New  (6th)  and 
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pages,  with  257  illustrations.     Cloth,  $4.50 ;  leather,  $5.50. 

FOTHERGILL  (J.  MILNER).  THE  PRACTITIONER'S  HAND-BOOK  OF 
TREATMENT.  Third  edition.  In  one  handsome  octavo  volume  of  664  pages. 
Cloth,  $3.75  ;  leather,  $4.75. 

FOWNES  (GEORGE).  A  MANUAL  OF  ELEMENTARY  CHEMISTRY  (IN- 
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FRANKLAND  (E.)  AND  JAPP  (F.  R.).    INORGANIC  CHEMISTRY.    In  one 

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FULLER  (EUGENE).  DISORDERS  OF  THE  SEXUAL  ORGANS  IN  THE 
MALE.  In  one  very  handsome  octavo  volume  of  238  pages,  with  25  engravings  and 
8  full-page  plates.     Cloth,  $2. 

FULLER  (HENRY).  ON  DISEASES  OF  THE  LUNGS  AND  AIR-PASSAGES. 
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GALLAUDET    (BERN    B.).      A    POCKET   TEXT-BOOK    ON  SURGERY. 

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GANT  (FREDERICK  JAMES).  THE  STUDENT'S  SURGERY.  A  Multum  in 
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GERRISH  (FREDERIC  H.).      A    TEXT-BOOK  OF  ANATOMY.     By  American 

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pages,   with  950  illustrations  in  black  and  colors.  Cloth,  $6.50;  flexible  water-proof, 
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TOLOGY.  Octavo  of  314  pages,  with  60  illustrations,  mostly  photographic.   Cloth,  $2.75. 

GOULD  (A.  PEARCE).  SURGICAL  DIAGNOSIS.  In  one  12mo.  volume  of  589 
pages.     Cloth,  $2.     See  Students'  Series  of  Manuals,  page  14. 

GRAY  (HENRY).  ANATOMY,  DESCRIPTIVE  AND  SURGICAL.  New 
American  edition  thoroughly  revised.  In  one  imperial  octavo  volume  of  1239  pages, 
with  772  large  and  elaborate  engravings.  Price  with  illustrations  in  colors,  cloth,  $7 ; 
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GREEN  (T.  HENRY).  AN  INTRODUCTION  TO  PATHOLOGY  AND  MOR- 
BID ANATOMY.  New  (8th)  American  from  eighth  and  revised  English  edition. 
Oct.  595  pages,  with  215  engravings  and  a  colored  plate.     Cloth,  $2.50,  net. 

GREENE  (WILLIAM  H.).  A  MANUAL  OF  MEDICAL  CHEMISTRY.  For 
the  Use  of  Students.  Based  upon  Bowmajj's  Medical  Chemistry.  In  one  12mo.  volume 
of  310  pages,  with  74  illustrations.     Cloth,  $1.75. 

GRINDON  (JOSEPH).     A    POCKET   TEXT-BOOK  OF  SKIN  DISEASES. 

12mo.  of  350  pages,  with  many  illustrations.     Shortly. 

GROSS  (SAMUEL  D.).  A  PRACTICAL  TREATISE  ON  THE  DISEASES, 
INJURIES  AND  MALFORMATIONS  OF  THE  URINARY  BLADDER, 
THE  PROSTATE  GLAND  AND  THE  URETHRA.  Third  edition,  revised  by 
Samuel  W.  Gross,  M.D.      Octavo  of  574  pages,  with  170  illustrations.     Cloth,  $4.50. 

HABERSHON  (S.  0.).  ON  THE  DISEASES  OF  THE  ABDOMEN,  comprising 
those  of  the  Stomach,  CEsophagus,  Caecum,  Intestines  and  Peritoneum.  Second  Amer- 
ican from  the  third  English  edition.  In  one  octavo  volume  of  554  pages,  with  11  engrav- 
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598  pages,  with  72  engravings.     Cloth,  |4. 

HARD  AW  AY  (W.  A.).  MANUAL  OF  SKIN  DISEASES.  New  (2d)  edition. 
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HARE  (HOB ART  AMORY).  A  TEXT-BOOK  OF  PBACTICAL  THEBA- 
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and  their  Employment  upon  a  Rational  Basis.  With  articles  on  various  subjects  by  well- 
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HARTSHORNE  (HENRY).  ESSENTIALS  OF  THE  PBINCIPLES  AND 
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A  CONSPECTUS  OF  THE  MEDICAL  SCIENCES.    Comprising  Manuals 


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HAYEM  (GEORGES)  AND  HARE  (H.  A.).  PHYSICAL  AND  NATUBAL 
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HERMANN  ( L. ) .  EXPEBIMENTAL  PHABMA COL OGY.  A  Handbook  of  the 
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HIRST  (BARTON  C.)  AND  PIERSOL  (GEORGE  A.).  HUMAN  MONSTBOS- 
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HODGE  (HUGH  L.).  ON  DISEASES  PECULIAR  TO  W03IEN,  INCLUDING 
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HUDSON  (A.).  LECTURES  ON  THE  STUDY  OF  FEVER.  In  one  octavo 
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IN  THE  LATIN  CHURCH.     In  three  octavo  volumes  of  about  500  pages  each. 
Per  volume,  cloth,  $3.     Complete  work  just  ready. 

FORMULARY   OF    THE   PAPAL   PENITENTIARY.     In    one  octavo 


volume  of  221  pages,  with  frontispiece.     Cloth,  $2.60. 


STUDIES  IN  CHURCH  HISTORY.  The  Rise  of  the  Temporal  Power- 
Benefit  of  Clergy — Excommunication.  New  edition.  In  one  handsome  12mo.  volume 
of  605  pages.     Cloth,  $2.50. 

SUPERSTITION  AND  FORCE;  ESSAYS  ON  THE  WAGER  OF  LAW, 


THE    WAGER    OF  BATTLE,   THE   ORDEAL   AND    TORTURE.     Fourth 
edition,  thoroughly  revised.     In  one  royal  12mo.  volume  of  629  pages.     Cloth,  $2.75, 

AN  HISTORICAL  SKETCH  OF  SACERDOTAL  CELIBACY  IN  THE 


CHRISTIAN  CHURCH.     Second  edition.     In  one  handsome  octavo  volume  of  685 
pages.     Cloth,  $4.50. 

LOOMIS  (ALFRED  L.)  AND  THOMPSON  (W.  GILMAN),  Editors.  A  SYS- 
TEM OF  PRA  CTICAL  MEDICINE.  In  Contributions  by  Various  American  Authors. 
In  four  very  handsome  octavo  volumes  of  about  900  pages  each,  fully  illustrated  in  black 
and  colors.  Complete  work  now  ready.  Per  volume,  cloth,  $5;  leather,  $6;  half 
Morocco,  $7.  For  sale  by  subscription  only.  Full  prospectus  free  on  application  to  the 
Publishers. 

LUFF  (ARTHUR  P.).  MANUAL  OF  CHEMISTRY,  for  the  use  of  Students  of 
Medicine.     In  one  12mo.  volume  of  522  pages,  with  36  engravings.     Cloth,  $2.     See 

Students'  Series  of  Manuals,  page  14. 

LYMAN  (HENRY  M.).  THE  PRACTICE  OF  MEDICINE.  In  one  very  hand- 
some octavo  volume  of  925  pages  with  170  engravings.     Cloth,  $4.75 ;  leather,  $5.75. 

LYONS  (ROBERT  D.),     A  TREATISE  ON  FEVER.     In  one  octavo  volume  of  362 

pages.     Cloth,  $2.25. 

MACKENZIE  (JOHN  NOLAND).  THE  DISEASES  OF  THE  NOSE  AND 
THROAT.     Octavo,  of  about  600  pages,  richly  illustrated.     Preparing, 

MAISCH    (JOHN  M.).    A  MANUAL    OF   ORGANIC  MATERIA   MEDIC  A. 

New  (7th)  edition,  thoroughly  revised  by  H.  C.  C.  Maisch,  Ph.G.,  Ph.D.     In  one  very 
handsome  12mo.  of  512  pages,  with  285  engravings.     Cloth,  $2.50,  net. 

MALSBARY  (GEO.  E.).  A  POCKET  TEXT-BOOK  OF  THEORY  AND 
PRACTICE  OF  MEDICINE.  12mo.  405  pages,  with  45  illustrations.  Just  Ready. 
Cloth,  $1.75,  net;  flexible  red  leather,  $2.25,  net. 

MANUALS.  See  Student^  Quiz  Series,  page  14,  Students'  Series  of  Manuals,  page  14,  and 
Series  of  Clinical  Manuals,  page  13. 

MARSH  (HOWARD).  DISEASES  OF  THE  JOINTS.  In  one  12mo.  volume  of 
468  pages,  with  64  engravings  and  a  colored  plate.  Cloth,  |2.  See  Series  of  Clinical 
Manuals,  page  13. 

Philadelphia,  706,  708  and  710  Sansom  St— New  York,  111  Fifth  Avenue. 


LEA     BROTHERS    &     CO:S    PUBLICATIONS.  11 

MARTIN  (EDWARD.)     SURGICAL   DIAGNOSIS.     One  12mo.   volume  of  400 

pages,  richly  illustrated.     Preparing. 

MARTIN  (WALTON)  AND  ROCKWELL  (W.  H.,  JR.).  A  POCKET  TEXT- 
BOOK OF  CHEMISTRY  AND  PHYSICS.  Vlmo.  366  pages,  with  137  illus- 
trations.    Just  ready.     Cloth,  $1.50,  net ;  flexible  red  leather,  $2.00,  net. 

MAY    (C.  H.).     MANUAL  OF  THE  DISEASES  OF  WOMEN.     For  the  use  of 

Students  and  Practitioners.     Second  edition,  revised  by  L.  S.  Rau,  M.D.     In  one  12mo. 
volume  of  360  pages,  wnth  3]  engravings.     Cloth,  $1.75. 

MEDICAL  NEWS  POCKET  FORMULARY.    See  page  1. 

MITCHELL  (JOHN  K.).  REMOTE  CONSEQUENCES  OF  INJURIES  OF 
NERVES  AND  THEIR  TREATMENT.  In  one  handsome  12mo.  volume  of  239 
pages,  with  12  illustrations.     Cloth  $1.75. 

MITCHELL  (S.  WEIR).  CLINICAL  LESSONS  ON  NERVOUS  DISEASES. 
In  one  very  handsome  12mo.  volume  of  299  pages,  with  17  engravings  and  2  colored  plates. 
Cloth,  $2.o0. 

MORRIS  (MALCOLM).  DISEASES  OF  THE  SKIN.  New  (2d)  edition.  In  one 
12mo.  volume  of  601  pages,  with  10  chromo-lithographic  plates  and  26  engravings. 
Cloth,  $3.25,  net. 

MULLER  (J.).    PRINCIPLES  OF  PHYSICS  AND  METEOROLOGY.     In  one 

large  Svo.  volume  of  623  pages,  with  538  engravings.     Cloth,  $4. 50. 

MUSSER  (JOHN  H.).  A  PRACTICAL  TREATISE  ON  MEDICAL  DIAG- 
NOSIS, for  Students  and  Physicians.  New  (3d)  edition.  In  one  octavo  volume  of 
1082  pages,  with  253  engravings  and  48  full-page  colored  plates.  Just  Ready.  Cloth, 
$6.00,  net;  leather,  $7.00,  net. 

NATIONAL  DISPENSATORY.     See  Stme,  Maisch  &  Caspan,  page  14. 

NATIONAL    FORMULARY.      See  National  Dispensatory,  page  14. 

NATIONAL  MEDICAL  DICTIONARY.    See  BiUings,  page  3. 

NETTLESHIP  (E.).  DISEASES  OF  THE  EYE.  New  (6th)  American  from  sixth 
English  edition.  Thoroughly  revised.  In  one  12mo.  volume  of  562  pages,  with  192 
engravings,  5  colored  plates,  test-types,  formulae  and  color-blindness  test.  Just  Ready. 
Cloth,  82.25,  net. 

NICHOLS  (JOHN  B.)  AND  VALE  (F.  P.).  A  POCKET  TEXT-BOOK  OF 
HISTOLOGY  AND  PATHOLOGY.  12mo.  of  459  pages,  with  213  illustrations. 
Just  ready.     Cloth,  $1.75,  net;  flexible  red  leather,  $2.25,  n^t. 

NORRIS  (WM.  F.)  AND  OLIVER  (CHAS.  A.).  TEXT-BOOK  OF  OPHTHAL- 
MOLOGY. In  one  octavo  volume  of  641  pages,  with  357  engravings  and  5  colored 
plates.     Cloth,  $5  ;  leather,  $6. 

OWEN  (EDMUND).  SURGICAL  DISEASES  OF  CHILDREN.  In  one  12mo. 
volume  of  525  pages,  with  85  engravings  and  4  colored  plates.  Cloth,  $2.  See  Series  of 
Clinical  Manuals,  page  13. 

PARK  (WILLIAM  H.).    BACTERIOLOGY  IN  MEDICINE  AND  SURGER  Y. 

12mo.  688  pages,  with  87  engravings  in  black  and  colors  and  2  colored  plates.     Just 
Ready.     Cloth,  $3.00,  net. 

PARK  ( ROSWELL),  Edit9r.  A  TREA  TISE  ON  S UR GER  Y,  by  American  Authors. 
For  Students  and  Practitioners  of  Surgery  and  Medicine.  New  condensed  edition. 
In  one  large  octavo  volume  of  1261  pages,  with  625  engravings  and  38  plates.  Just 
Ready.  Cloth,  net,  $6.00;  leather,  net,  $7.00.  8®"This  work  is  published  also  in  a 
large  edition,  comprising  two  octavo  volumes.  Vol.  I.,  General  Surgery,  799  pages,  with 
356  engravings  and  21  full-page  plates  in  colors  and  monochrome.  Vol.  II.,  Special 
Surgery,  796  pages,  with  451  engravings  and  17  full-page  plates  in  colors  and  mono- 
chrome.    Price  per  volume,  cloth,  $4.50;  leather,  $5.50,  net. 

PARVIN  (THEOPHILUS).  THE  SCIENCE  AND  ART  OF  OBSTETRICS. 
Third  edition  In  one  handsome  octavo  volume  of  677  pages,  with  267  engravings  and 
2  colored  plates.     Cloth,  $4.25;  leather,  $5  25. 


Philadelphia,  706,  708  and  710  Sansom  St — New  York,  111  Fifth  Avenue. 


12  LEA    BROTHERS    &     CO.'S    PUBLICATIONS. 

PEPPER'S  SYSTEM  OF  MEDICINE.    See  page  2. 

PEPPER  (A.  J.).  SURGICAL  PATHOLOGY.  In  one  12mo  volume  of  511  pages, 
with  81  engravings.     Cloth,  $2.     See  Students'  Series  of  Manuals,  page  14. 

PICK  (T.  PICKERING).     FRACTURES  AND  DISLOCATIONS.    In  one  12mo. 

volume  of  530  pages,  with  93  engravings.    Cloth,  $2.    See  Series  of  Clinical  Manuals,  p.  13. 

PL  A  YF  AIR  (W.  S.).  A  TREATISE  ON  THE  SCIENCE  AND  PRACTICE 
OF  MIDWIFERY.  Kew  (7th)  American  from  the  Ninth  English  edition.  In  one 
octavo  volume  of  700  pages,  with  207  engravings  and  7  full  page  plates.  Cloth,  $3.75, 
net;  leather,  $4.75,  net. 

THE  SYSTEMATIC  TREATMENT  OF  NERVE  PROSTRATION  4.ND 


HYSTERIA.     In  one  12mo.  volume  of  97  pages.     Cloth,  $1. 

OLITZER  (ADAM).  A  TEXT-BOOK  OF  THE  DISEASES  OF  THE  EAR 
AND  ADJACENT  ORGANS.  Second  American  from  the  third  German  edition. 
In  one  octavo  volume  of  748  pages,  with  330  original  engravings. 

POCKET  FORMULARY.    See  page  1. 

POCKET  TEXT-BOOKS  Cover  the  entire  domain  of  medicine  in  sixteen  volumes  of 
350  to  450  pages  each,  written  by  teachers  in  leading  American  medical  colleges. 
Issued  under  the  editorial  supervision  of  Bern  B.  Gat.t.audet,  M.D.  ,  of  the  College  of 
Physic  ans  and  Surgeons,  New  York.  Thoroughly  modern  and  authoritative,  concise 
and  clear,  amply  illustrated  with  engravings  and  plates,  handsomely  printed  and 
bound.  I?he  series  is  constituted  as  follows  :  Anatomy  (preparing^,  Physiology  {ready), 
Chemistry  and  Physics  {ready),  Histology  and  Pathology  {ready\  Materia  Medica, 
Therapeutics,  Medical  Pharmacy,  Prescription  Writing  and  Medical  Latin  {ready), 
Practice  {ready),  Diagnosis  {shortly),  Nervous  and  Mental  Diseases  {ready),  Surgery 
{ preparing),  Genito- Urinary  and  Veneieal  Diseases  (preparing).  Skin  Diseases 
(preparing).  Eye,  Ear,  Nose  and  Throat  {shortly),  Obstetdcs  {shortly).  Gynecology 
(ready),  Diseases  of  Children  {ready),  Bacteriology  and  Hvgiene  {shortly).  For  further 
details  see  under  respective  authors  in  this  catalogue.  Special  circular  free  on  appli- 
cation. 

POTTS  fCHAS.  S.).  A  POCKET  TEXT-ROOK  OF  NERVOUS  AND 
MENTAL  DISEASES.  12mo.  of  455  pages,  with  88  illlustrations.  Just  ready. 
Cloth,  §1.75,  net;  flexible  red  leather,  §2.25,  net. 

PROGRESSIVE  MEDICINE.    See  page  1. 

PURDY  (CHARLES  W.).  BRIGHT' S  DISEASE  AND  ALLIED  AFFEC- 
TIONS OF  THE  KIDNEY.  In  one  octavo  volume  of  288  pages,  with  18  engrav- 
ings.    Cloth,  $2. 

PYE-SMITH  (PHILIP  H.).  DISEASES  OF  THE  SKIN.  In  one  12mo.  volume 
of  407  pages,  with  28  illustrations,  18  of  which  are  colored.     Cloth,  $2. 

QUIZ  SERIES.     See  Students'  Quiz  Series,  page  14. 

RALFE  (CHARLES  H.).  CLINICAL  CHEMISTRY.  In  one  12mo.  volume  of 
314  pages,  with  16  engravings.     Cloth,  $1.50.     See  Students'  Series  of  Manuals,  page  14. 

EAMSBOTHAM  (FRANCIS  H.).  THE  PRINCIPLES  AND  PRACTICE  OF 
OBSTETRIC  MEDICINE  AND  SURGERY.  Imperial  octavo,  of  640  pages, 
with  64  plates  and  numerous  engravings  in  the  text.      Leather,  $7. 

REMSEN  (IRA).  THE  PRINCIPLES  OF  THEORETICAL  CHEMISTRY. 
Sew  (5th)  edition,  thoroughly  revised.     In  one  12mo.  volume  of  326  pages.     Cloth,  $2. 

RICHARDSON   (BENJAMIN  WARD).    PREVENTIVE  MEDICINE.    In  one 

octavo  volume  of  729  pages.     Cloth,  $4 ;  leather,  $5. 

ROBERTS  (JOHN  B.).  THE  PRINCIPLES  AND  PRACTICE  OF  MODERN 
SURGERY.  New  (2dj  edition.  In  one  octavo  volume  of  838  pages,  with  474 
engravings  and  8  plates.     Just  Ready.     Cloth,  $4.25,  net;  leather,  $5.25,  net. 

THE  COMPEND  OF  ANATOMY.     For  use  in  the  Dissecting  Room  and  in 

preparing  for  Examinations.     In  one  16mo.  volume  of  196  pages.     Limp  cloth,  75  cents. 


Philadelphia,  706,  708  and  710  Sansom  St.— New  York,  111  Fifth  Avenue. 


LEA     BROTHERS    &     CO.'S    PUBLICATIONS.  13 

ROSS  (JAMES).    A  HANDBOOK  OF  THE  DISEASES  OF  THE  NERVOUS 

SYSTEM.     In  one  handsome  octavo  volume  of  726  pages,  with  184  engravings.     Cloth, 

$4. 50 ;  leather,  |5. 50. 

SCHAFER  (EDWARD  A.).  THE  ESSENTIALS  OF  HISTOLOG  Y,  DESCRIP- 
TIVE AND  PRACTICAL.  For  the  use  of  Students.  New  (5th)  edition.  In  one 
handsome  octavo  volume  of  350  pages,  with  325  illustrations.    Cloth,  $3,  net. 

A    COURSE    OF  PRACTICAL    HISTOLOGY.     Second   edition.     In    one 


12mo.  volume  of  307  pages,  with  59  engravings.     Cloth,  $2.25. 

SCHLEIF  (WM.).  A  POCKET  TEXT-BOOK  OF  MATERIA  MEDIC  A, 
THERAPEUTICS,  PRESCRIPTION  WRITING.  MEDICAL  LATIN  AND 
MEDICAL  PHARMACY.  12mo.  352  pages.  Just  Ready.  Cloth,  §1.50,  net; 
flexible  red  leather,  $2.00,  net. 

SCHMITZ  AND  ZUMPT'S  CLASSICAL  SERIES. 

ADVANCED  LATIN  EXERCISES     Cloth,  60  cents;  half  bound,  70  cents. 
SCHMITZ' S  ELEMENTARY  LATIN  EXERCISES.     Cloth,  50  cents. 
SALL  UST.     Cloth,  60  cents ;  half  bound,  70  cents. 
NEPOS.     Cloth,  60  cents ;  half  bound,  70  cents. 
VIRGIL.     Cloth,  85  cents;  half  bound,  $1. 
CURTIUS.     Cloth,  80  cents;  half  bound.  90  cents. 

SCHOFIELD  (ALFRED  T.).  ELEMENTARY  PHYSIOLOGY  FOR  STU- 
DENTS. In  one  12mo.  volume  of  380  pages,  with  227  engravings  and  2  colored  plates. 
Cloth,  $2. 

SCHREIBER  (JOSEPH).  A  MANUAL  OF  TREATMENT  BY  MASSAGE 
AND  METHODICAL  MUSCLE  EXERCISE.  Translated  by  Waiter  AIe>'del- 
SON,  M.  D. ,  of  New  York.  In  one  handsome  octavo  volume  of  274  pages,  with  117  fine 
engravings. 

SENN  (NICHOLAS).  SURGICAL  BACTERIOLOGY.  Second  edition.  In  one 
octavo  volume  of  268  pages,  with  13  plates,  10  of  which  are  colored,  and  9  engravings. 
Cloth,  $2. 

SERIES  OF  CLINICAL  MANUALS.  A  Series  of  Authoritative  Monographs  on 
Important  Clinical  Subjects,  in  12mo.  volumes  of  about  550  pages,  well  illustrated.  The 
following  volumes  are  now  ready :  Yeo  on  Food  in  Health  and  Disease,  new  (2d) 
edition,  S2.50;  Carter  and  Frost's  Ophthalmic  Surgery,  $2.25;  Marsh  on  Diseases 
of  the  Joints,  $2 ;  Owen  on  Surgical  Diseases  of  Children,  $2 ;  Pick  on  Fractures  and 
Dislocations,  $2. 
For  separate  notices,  see  under  various  authors'  names. 

SERIES  OF  POCKET  TEXT-BOOKS.    See  page  12. 

SERIES  OF  STUDENTS'  MANUALS.    See  next  page. 

SIMON  (CHARLES  E.).  CLINICAL  DIAGNOSIS,  BY  MICROSCOPICAL 
AND  CHEMICAL  METHODS.  New  (3d)  and  revised  edition.  In  one  handsome 
octavo  volume  of  563  pages,  with  138  engravings  and  18  full-page  plates  in  colors. 
Just  Ready.     Cloth,  83.50,  net. 

SIMON  (W.).  MANUAL  OF  CHEMISTRY.  A  Guide  to  Lectures  and  Laboratory 
Work  for  Beginners  in  Chemistry.  A  Text-book  specially  adapted  for  Students  of  Phar- 
macy and  Medicine.  New  (6th)  edition.  In  one  8vo.  volume  of  536  pages,  with  46 
engravings  and  8  plates  showing  colors  of  64  tests.     Cloth,  §3.00,  n£t. 

SLADE(D.  D.).  DIPHTHERIA  ;  ITS  NATURE  AND  TREATMENT.  Second 
edition.     In  one  royal  12mo.  volume,  158  pages.     Cloth,  $1.25. 

SMITH  (EDWARD).     CONSUMPTION;   ITS  EARLY  AND   TtEMEDIABLE 

STAGES.     In  one  8vo.  volume  of  253  pages.     Cloth,  $2.25. 

SMITH  (J.  LEWIS).  A  TREATISE  ON  THE  DISEASES  OF  INFANCY 
AND  CHILDHOOD.  Eighth  edition,  thoroughly  revised  and  rewritten  and  greatly 
enlarged.  In  one  large  8vo.  volume  of  983  pages,  with  273  illustrations  and  4  full- 
page  plates.     Cloth,  $4.50;  leather,  §5.50. 


Philadelphia,  706,  708  and  710  Sansom  St— New  York,  111  Fifth  Avenue. 


14  LEA    BROTHERS    &     CO.'S    PUBLICATIONS. 

SMITH  (STEPHEN).  OPERATIVE  SURGERY.  Second  and  thoroughly  revised 
edition.     In  one  octavo  vol.  of  892  pages,  with  1005  engravings.     Cloth,  $4 ;  leather,  |5 

SOLLY    (S.    EDWIN).     A   HANDBOOK   OF  MEDICAL    CLIMATOLOGY. 

In  one  handsome  octavo  volume  of  462  pages,  with  engravings  and  11  full-page  plates, 
5  of  which  are  in  colors.     Cloth,  $4.00. 

STILLE  (ALFRED).  CHOLERA;  ITS  ORIGIN,  HISTORY,  CAUSATION, 
SYMPTOMS,  LESIONS,  PREVENTION  AND  TREATMENT.  In  one  12mo. 
volume  of  163  pages,  with  a  chart  showing  routes  of  previous  epidemics.     Cloth,  $1.25. 

THERAPEUTICS  AND  MATERIA  MEDIC  A.    Fourth  and  revised  edition. 


In  two  octavo  volumes,  containing  1936  pages.     Cloth,  $10 ;  leather,  $12. 

STILLE   (ALFRED),  MAISCH   (JOHN   M.)   AND   CASPARI   (CHAS.   JR.). 

THE  NATIONAL  DISPENSATORY:^  Containing  the  Natural  History,  Chemistry, 
Pharmacy,  Actions  and  Uses  of  Medicines,  including  those  recognized  in  the  latest  Phar- 
macopoeias of  the  United  States,  Great  Britian  and  Germany,  with  numerous  references 
to  the  French  Codex.  Fifth  edition,  revised  and  enlarged  in  accordance  with  and  em- 
bracing the  new  U.  S.  Pharmacopoeia,  Seventh  Decennial  Eevision.  With  Supplement 
containing  the  new  edition  of  the  National  Formulary.  In  one  magnificent  imperial 
octavo  volume  of  2025  pages,  with  320  engravings  Cloth,  $7. 25 ;  leather,  $8.  With 
ready  reference  Thumb-letter  Index.     Cloth,  $7.75 ;  leather,  $8.50. 

STIMSON  (LEWIS  A.).    A  MANUAL   OF  OPERATIVE  SURGERY.    New 

(4th)  edition.  In  one  royal  12mo.  volume  of  581  pages,  with  293  engravings.  Cloth,  $3.00, 
net.     Just  Ready. 

A  TREATISE  ON  FRACTURES  AND  DISLOCATIONS.  In  one  hand- 
some octavo  volume  of  831  pages,  with  326  engravings  and  20  full-page  plates.  Cloth, 
$5  ;  leather,  $6,  net. 

STUDENTS'  QUIZ  SERIES.  A  New  Series  of  Manuals  in  question  and  answer  for 
Students  and  Practitioners,  covering  the  essentials  of  medical  science.  Thirteen  volumes, 
pocket  size,  convenient,  authoritative,  well  illustrated,  handsomely  bound  in  limp  cloth, 
and  issued  at  a  low  price.  1.  Anatomy  (double  number);  2.  Physiology;  3.  Chemistry 
and  Physics ;  4.  Histology,  Pathology  and  Bacteriology ;  5.  Materia  Medica  and  Thera- 
peutics ;  6.  Practice  of  Medicine ;  7.  Surgery  (double  number) ;  8.  Genito-Urinary  and 
Venereal  Diseases ;  9.  Diseases  of  the  Skin ;  10.  Disieases  of  the  Eye,  Ear,  Throat  and 
Nose ;  11.  Obstetrics ;  12.  Gynecology ;  13.  Diseases  of  Children.  Price,  $1  each,  except 
Nos.  1  and  7,  Anatomy  and  Surgery,  which  being  double  numbers  are  priced  at  $1. 75  each. 
Full  specimen  circular  on  application  to  publishers. 

STUDENTS'  SERIES  OF  MANUALS.  A  Series  of  Fifteen  Manuals  by  Eminent 
Teachers  or  Examiners.  The  volumes  are  pocket-size  12mos.  of  from  300-540  pages,  pro- 
fusely illustrated,  and  bound  in  red  limp  cloth.  The  following  volumes  may  now  be 
announced:  Herman's  First  Lines  in  Midwifery,  $1.25;  Luff's  Manual  of  Chemistry, 
$2;  Brtjce's  Materia  Medica  and  Therapeutics  (sixth  edition),  $1.50,  net;  Gould's  Sur- 
gical Diagnosis,  $2;  Klein's  Elements  of  Histology  (5th  edition),  $2.00,  net;  Pepper's 
Surgical  Pathology,  $2;  Treves'  Surgical  Applied  Anatomy,  $2;  Ealpe's  Clinical 
Chemistry,  $1.50;  and  Clarke  and  Lockvs^ood's  Dissector's  Manual,  $1.50 
For  separate  notices,  see  under  various  authors'  names. 

STURGES  (OOTAVIUS).  AN  INTRODUCTION  TO  THE  STUDY  OF  CLIN- 
ICAL MEDICINE.     In  one  12mo.  volume.     Cloth,  $1.25. 

SUTTON  (JOHN  BLAND).  SURGICAL  DISEASES  OF  THE  OVARIES 
AND  FALLOPIAN  TUBES.  Including  Abdominal  Pregnancy.  In  one  12mo.  vol- 
ume of  513  pages,  with  119  engravings  and  5  colored  plates.     Cloth,  $3. 

T AIT  (L AWSON ' .    DISEASES  OF  WOMEN  AND  ABD OMINAL  SURGERY 

Vol.  1.  contains  554  pages,  62  engravings,  and  3  plates.     Cloth,  $3. 

TANNER   (TH01O.S   HAWKES).     ON  THE  SIGNS  AND  DISEASES   OF 

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TAYLOR  (ALFRED  S.).  MEDICAL  JURISPRUDENCE.  New  American 
from  the  twelfth  English  edition,  specially  revised  by  Clark  Bell,  Esq.,  of  the  N.  Y. 
Bar.  In  one  octavo  volume  of  831  pages,  with  54  engravings  and  8  full-page  plates. 
Cloth,  $4.50;  leather,  15.50. 

ON   POISONS    IN    RELATION    TO    MEDICINE    AND    MEDICAL 

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TAYLOR  (ROBERT  W.).  THE  PATHOLOGY  AND  TREATMENT  OF 
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A  PRACTICAL  TREATISE  ON  SEXUAL  DISORDERS  IN  THE  MALE 

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A    CLINICAL    ATLAS    OF    VENEREAL    AND    SKIN    DISEASES. 


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THOMAS    (T.   GAILLARD)    AND   MUNDE  (PAUL     F.).   A    PRACTICAL 

TREATISE  ON  THE  DISEASES  OF  WOMEN.  Sixth  edition,  thoroughly 
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THOMPSON  (W.  GILMAN).  A  TEXT-BOOK  OF  PRACTICAL  MEDICINE. 
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THOMPSON  (SIR  HENRY).  CLINICAL  LECTURES  ON  DISEASES  OF 
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203  pages,  with  25  engravings.     Cloth,  $2.25. 

THE  PATHOLOGY  AND   TREATMENT  OF  STRICTURE  OF  THE 

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THOMSON  (JOHN).  A  GUIDE  TO  THE  CLINICAL  EXAMINATION  AND 
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TODD  (ROBERT  BENTLEY).  CLINICAL  LECTURES  ON  CERTAIN 
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TREVES  (FREDERICK).  OPERATIVE  SURGERY.  In  two  8vo.  volumes  con- 
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A  SYSTEM  OF  SURGERY.  In  Contributions  by  Twenty-five  English  Sur- 
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SURGICAL   APPLIED    ANATOMY.     In  one  12mo.  volume  of  583  pages, 


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TUTTLE  (GEO.  M.).  A  POCKET  TEXT-BOOK  OF  DISEASES  OF 
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16  LEA    BROTHERS    &     CO.'S    PUBLICATIONS. 

VAUGHAN    (VICTOR    C.>   AND  NOVY    (FREDERICK  G.).     PTOMAINS, 

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VISITING  LIST.  THE  MEDICAL  NEWS  VISITING  LIST  for  1900.  Four 
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WATSON  (THOMAS).  LECTURES  ON  TBE  PRINCIPLES  AND  PRAC- 
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190  engravings.     Cloth,  $9 ;  leather,  $11. 

WEST  (CHARLES).  LECTURES  ON  THE  DISEASES  PECULIAR  TO 
WOMEN.  Third  American  from  the  third  English  edition.  In  one  octavo  volume  of 
543  pages.     Cloth,  $3.75;  leather,  $4.75. 

ON  SOME  DISORDERS  OF  THE  NERVOUS  SYSTEM  IN  CHILD- 


HOOD.    In  one  small  12mo.  volume  of  127  pages.     Cloth,  $1. 

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WHITLA  (WILLIAM).  DICTIONARY  OF  TREATMENT,  OR  THERA- 
PEUTIC INDEX.  Including  Medical  and  Surgical  Therapeutics.  In  one  square 
octavo  volume  of  917  pages.     Cloth,  $4. 

WILLIAMS  (DAWSON).  MEDICAL  DISEASES  OF  INFANCY  AND 
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$2.50,  net. 

WILSON  (ERASMUS).  A  SYSTEM  OF  HUMAN  ANATOMY.  A  new  and 
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one  octavo  volume  of  616  pages.     Cloth,  $4 ;  leather,  $5. 

WINCKEL  ON  PATHOLOGY  AND  TREATMENT  OF  CHILDBED     In  one 

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WIPPERN  (A.  G.)  AND  BALLENGER  (W.  L.).  A  POCKET  TEXT-BOOK 
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about  400  pages  with  many  illustrations.     Shortly. 

WOHLER'S  OUTLINES  OF  ORGANIC  CHEMISTRY  Translated  from  the 
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YEAR  BOOK  OF  TREATMENT  FOR  1898.  A  Critical  Review  for  Practitioners  ot 
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YEO  (I.  BURNEY).  FOOD  IN  HEALTH  AND  DISEASE.  New  (2d)  edition. 
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Clinical  Manuals,  page  13. 

YOUNG  (JAMES  K.),_  ORTHOPEDIC  SURGERY.  In  one  8vo  volume  of  475 
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COLUMBIA  UNI 

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A  text-book  of  dental  pathology  and jher 


